Update meld to 3.15.0:

2015-10-05 meld 3.15.0
======================

  Features:

  * New API for version control plugins with more consistent interfaces and
    data structures across different plugins, enabling many minor
    improvements (Kai Willadsen)
    * Support the conflict resolution prompt in file comparisons for all VCs
    * Improve caching behaviour for some version control plugins
    * Better sensitivity handling for version control actions
    * Cache and show more metadata (e.g., file renames)
    * Several version control plugins have not been ported to the new API; the
      current list of support plugins is: Git, Mercurial, Subversion 1.7+,
      Bazaar
  * Faster rendering in file comparison view, enabled by new GtkTextView API
    (Kai Willadsen)
  * Move to using GtkSourceView style schemes with Meld-specific colour tags
    for highlight colours; this lets themes include colours that match the
    sourceview theme (Kai Willadsen)
  * Offer to open binary files externally (Pratik Dayama)
  * Show the common ancestor in conflicting regions (and the merged file
    everywhere else) when viewing conflicts through Meld's version control
    view; currently this is only supported under Git (Kai Willadsen)
  * Support showing staged/partially staged status of files under Git (Kai
    Willadsen)
  * Update preferences dialog to new style with headerbar (Kai Willadsen)

  Fixes:

  * Documentation updates (Andrew Beyer)
  * Fix crash with some GTK+ versions when using --output (Kai Willadsen)
  * Fix merge-all action not working at all (Kai Willadsen)
  * Fix creating patches with unicode path names (Kai Willadsen)
  * Fix copy-to-clipboard option in patch dialog (Kai Willadsen)
  * Fix diffmap alignment for new GTK+ allocation behaviour (Kai Willadsen)
  * Improve float accuracy in folder comparison timestamp resolution (Kai
    Willadsen)
  * Fix default SVN keyword filter to escape $ characters (Kai Willadsen)
  * Fix display of unicode --help from command line (Kai Willadsen)
  * Fix keyboard shortcut docs (Kai Willadsen)
  * Don't incorrectly show identical notification for changed folder
    comparisons (Kai Willadsen)

  Internal changes:

  * Requirements are now GTK+ 3.14, GtkSourceView 3.14 and GLib 2.36
  * Rewritten version control plugin API
  * Unified colour handling between linkmap, diffmap and file comparison
  * Move all textview drawing to a new GtkSourceView subclass, using the new
    GTK+ draw-layer API

  Translations:

  * Daniel Mustieles (es)
  * Gábor Kelemen (hu)
  * Jiri Grönroos (fi)
  * Josef Andersson (sv)
  * Marek Černocký (cs)
  * Piotr Drąg (pl)

(wiz)