Update contao42 to 4.2.5.

### 4.2.5 (2016-10-27)

* Unlock members after password change (see contao/core#8545).
* Register an alias for the language fallback page model (see
  contao/core#8544).
* Correctly calculate the maximum length of tl_files.name (see
  contao/core#8536).
* Correctly add the headline if a content element is versionized (see
  contao/core#8502).
* Optimize the DCA sorting filter for date fields (see contao/core#8485).
* Do not show version entries of deleted files (see contao/core#8480).
* Redirect the empty URL depending on language and alias name (see
  contao/core#8498).
* Apply `specialchars()` to widget attributes (see contao/core#8505).
* Queue the requests when rebuilding the search index (see contao/core#8449).
* Correctly determine the form field names in the file manager (see #600).
* Correctly show the maximum file size in the form upload widget (see #595).
* Correctly encode e-mail addresses in the text element (see #594).
* Do not parse front end templates twice (see #599).
* Correctly set host and scheme in the URL generator (see #592).
* Correctly reload the page and file trees in "edit multiple" mode.
* Correctly normalize the paths in the symlink command.

(taca)