Update to 0.7.4

* Use Qt5 instead of Qt4
* Use internal hunspell to avoid runtime error

Changelog:
Sigil 0.7.4 2013.10.27
    - Use numeric entity for non-breaking spaces (nbsp) instead of named
      entity. Fixes issues where files without a doctype won't open properly.

Sigil 0.7.3 2013.08.03
    - Fix issue 2309: Compile failure due to case issue on m_lastFolderOpen.
    - Fix issue 2269: "Conflicts with:" always in English.
    - Fix issue 2186: Sigil 0.7.2 crashes on "Add existing files".
    - Fix issue 2232: The nbsp characters in UTF-8 files are converted to normal spaces.
    - Fix issue 2201: Save does not prompt for filename if filename not set
      after cancelling save operation.
    - Fix issue 2193: Incorrect country code used for Serbia.
    - Implement issue 2199: Mac, Don't open empty book by default.

Sigil 0.7.2 2013.04.14
    - Implement issue 2129: Enhance archive filename encoding handling.
    - Implement issue 2128: Warnings for non-ASCII characters in filenames.
    - Implement issue 2113: Preview should zoom separately from other views.
    - Implement issue 1997: Tool to Add Cover image and file automatically.
    - Implement issue 1993: Find & Replace should have a Marked Text option.
    - Implement issue 2083: Enhance invalid OPF recovery.
    - Implement issue 2082: Improve performance of Book Browser refresh.
    - Fix issue 2170: Spellcheck should remember position after changing word.
    - Fix issue 2148: Don't delete cover image in "Delete unused media files".
    - Fix issue 2147: Doubleclick in Delete Files dialog can cause crash.
    - Fix issue 2143: Bulk rename with just a number for filename does not use correct number of 0s.
    - Fix issue 2121: Wait cursor shows when dialog is open while saving or opening.
    - Fix issue 2107: Heading not accepted due to split at end of file.
    - Fix issue 2110: Insert Special Character inserts wrong code for nnbsp.
    - Fix issue 2021: Importing UTF-16 encoded files results in empty file.
    - Fix issue 2088: Ctrl-click on text files does not work in Code View.
    - Fix Issue 2071: Anchor dialog has disabled text field.
    - Fix Issue 2077: Rename dialog incorrectly sized.
    - Fix issue 2081: Book Browser tooltips are not updated when semantics change or for cover images.
    - Fix issue 2080: OPF meta title not updated correctly for Add Semantic.
    - Fix issue 2079: UI Language dropdown does not show language names for entries containing _.

Sigil 0.7.1 2013.03.03
    - Implement issue 2058: Code View should be able to show resizable image.
    - Implement issue 2038: Spellcheck "change selected word to" should remember sorting order.
    - Implement issue 2043: Spellcheck should allow case-insensitive sorting.
    - Implement issue 2029: Save and open should warn if HTML files are not well formed.
    - Implement issue 2009: Add semantic tags to filenames in reports.
    - Implement issue 2028: Special characters should work in non-html files.
    - Implement issue 2027: Upgrade Boost to Boost 1.53.0.
    - Fix issue 2069: Work around for archives where filenames are not utf-8 encoded.
    - Fix issue 2068: ZIP general purpose bit 11 (utf-8) filename not set.
    - Fix issue 2061: Language code using wrong character to separate country code.
    - Fix issue 2057: Text selected across lines using Ctrl-F cannot be found with Find.
    - Fix issue 2036: Mark for Index can insert HTML tags into code making it invalid.
    - Fix issue 2041: Preview does not sync cursor after using Sigil for a while.
    - Fix issue 2030: The   character is incorrectly converted to space on open.
    - Fix issue 2035: Index Editor entries with nbsp character don't match text.
    - Fix issue 2016: Find with wrap off and All HTML Files still wraps on last file.
    - Fix issue 2001: Spellcheck does not always highlight a word the first time.
    - Fix issue 2017: Clips pasted into some windows does not work correctly.
    - Fix issue 2008: Index adds extra comma in some cases.

Sigil 0.7.0 2013.02.17
    - Implement issue 1983: Set the tooltips of files in Book Browser to the filename.
    - Implement issue 1965: Allow opening files that are missing container.xml.
    - Implement issue 1975: HTML TOC and Index should use CSS files instead of inline stylesheet.
    - Implement issue 1968: Bookmark location in editing window.
    - Implement issue 1963: Table Of Contents window should default to expanded when opened or refreshed.
    - Implement issue 1953: Allow entering a list of new words into dictionary preferences.
    - Implement issue 1952: Add shortcut for Copy HTML file.
    - Implement issue 1951: Doubleclick on Image Report file should find next use of image.
    - Implement issue 1949: Add support for multiple active user dictionaries.
    - Implement issue 1947: Spellcheck dialog to manage all misspelled words at once.
    - Implement issue 62: Add document's css styles to menu.
    - Implement issue 1945: Allow editing of CSS while displaying page.
    - Implement issue 1661: Report list of all different characters in the book.
    - Implement issue 1746: Add Report for Links and Footnotes.
    - Implement issue 1941: Add Find & Replace option to wrap or not wrap searches.
    - Implement issue 1940: Update Insert Image to Insert File to support insert of audio/video.
    - Implement issue 1938: Update Delete Image files to Delete Media files to include audio/video.
    - Implement issue 1937: Add Report for All Files.
    - Implement issue 1936: Add Clip Bar toolbar with buttons for Clips and shortcuts for Clips.
    - Implement issue 1931: Change to QRegularExpression for most regexes.
    - Implement issue 1185: Edit Table of Contents without needing Generate TOC.
    - Implement issue 1929: Add support for playing audio and video files.
    - Implement issue 917: Sigil should support audio and video tags.
    - Implement issue 1928: Add well-formed check to HTML File Report.
    - Implement issue 1864: Allow Metadata Editor dialog to stay open while editing.
    - Implement issue 1871: Code View context menu should show clips even if word is misspelled.
    - Implement issue 1870: Saved Searches should use mode settings from Find & Replace.
    - Implement issue 1927: Add support for basic replacement Clips (e.g. span) in Book View.
    - Implement issue 20: Embedded fonts support.
    - Implement issue 1926: Upgrade to Qt5.
    - Implement issue 1924: Add dockable Clips window to select clips.
    - Implement issue 1925: Don't force well formed checks unless absolutely necessary.
    - Implement issue 1843: Preview should be real-time display of Code View.
    - Fix issue 1989: Problem with nested index entries.
    - Fix issue 1964: Correcting a word using spellcheck does not make file go to "not saved" state.
    - Fix issue 1961: Generate TOC should not create IDs for headings when it only points to filenames.
    - Fix issue 1857: CSS Highlighting inline styles inconsistent.
    - Fix issue 1946: Highlight misspelled words checkbox should be available in Preferences.
    - Fix issue 1943: Reports can crash if file has non well-formed xml.
    - Fix issue 1883: TOC window does not jump to right location for some entries.
    - Fix issue 1906: "Delete unused image files" deleting background images.
    - Fix issue 1874: Using Delete Unused Stylesheet Classes deletes pseudo-elements.
    - Fix issue 1939: CSS parser does not match wildcard selectors consistently.
    - Fix issue 1935: Improve speed of Index Editor autofill by removing progress dialog.
    - Fix issue 1891: Opening the Saved Searches expands all groups.
    - Fix issue 1934: Go To Style does not work with CSS filenames that have spaces in them.
    - Fix issue 1933: No message is displayed if Go To Style can't find a style.
    - Fix issue 1932: Replace All needs to be run twice in some cases.
    - Fix issue 1930: Fix Metadata language dropdown selection incorrect matching.
    - Fix issue 1775: Sigil-0.6.0 edit very slow with Thai e-Pub.
    - Fix issue 1764: Sigil crashes on KDE after rearranging text sections.
    - Fix issue 1720: Book View highlights text apparently randomly.
    - Fix issue 1923: CSS validation should use EPUB 2 profile.
    - Fix issue 1922: Invalid EPUB warning dialog is not long enough.
    - Fix issue 1918: Support import of tab separated entries for Index Editor.
    - Fix issue 1917: Keep selection when deleting unused images if an HTML file was selected.
    - Fix issue 1916: Allow Go To Style to work for link type text/x-oeb1-css.
    - Fix issue 1869: Backspace in Preferences - Shortcuts causes crash.
    - Fix issue 1818: Hyperlink of URL with & causes invalid code.
    - Fix issue 1824: Cursor position changes when saving the book.

(ryoon)