[easytag] (37 commits) Non-fast-forward update to branch wip/taglib-mp4-cxx

[David King <davidk src gnome org>]

The branch 'wip/taglib-mp4-cxx' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  7fb8964... Use C++ TagLib API instead of C wrapper
  7eb6618... MP4 TagLib C++ WIP

Commits added to the branch:

  47754d8... Avoid a potentially-uninitialised variable (*)
  5ce6487... Switch to use GTK+ 3 by default (*)
  b22129b... Show progress bar text with GTK+ 3 (*)
  c636cd0... Support reading tags from Ogg Opus files (*)
  2b685a8... Support for writing tags to Ogg Opus files (*)
  e8296e2... Fix reading header information from Opus files (*)
  32e494e... Update AppData for Opus file support (*)
  a6a18f5... Error out if Ogg disabled but Speex/Opus enabled (*)
  ee30ce1... Rearrange Opus/Speex Ogg checks (*)
  1d6c063... Updated Brazilian Portuguese translation (*)
  af6bf46... Mention Ogg Speex support in AppData description (*)
  67bdf5f... Update British English translation (*)
  46f71f0... Updated Polish translation (*)
  ba43621... Updated Brazilian Portuguese translation (*)
  4760689... Small optimization for scanner functions (*)
  8a5acff... Updated Spanish translation (*)
  a6b44d7... Reimplement Roman numeral detection (*)
  ea93fe3... Update about dialogue credits (*)
  e6adc18... Updated German translation (*)
  3b98360... Updated Czech translation (*)
  480e68f... Updated Serbian translation (*)
  c7b7372... Updated French translation (*)
  3c7afc6... Updated French translation (*)
  87fe06a... Fix typo in proxy tooltip string (*)
  8cdd814... Updated Spanish translation (*)
  bf7256b... Updated German translation (*)
  e92d01d... Updated Polish translation (*)
  b34a228... Split scanner dialog off into scan_dialog.[c|h] (*)
  55bc129... Add a test for scanner string functions (*)
  f43c0a6... Improve scanner functions and fix tests (*)
  30a0e93... Add simple performance tests for scanner functions (*)
  00ab3f4... Use gtester and add test and report make targets (*)
  d8d6d47... [l10n] Updated Italian translation. (*)
  6d878e8... Avoid NULL deref in Scan_Rename_File_Prefix_Path() (*)
  745e88d... Update British English translation (*)
  2dfb417... Use C++ TagLib API for MP4 tags
  26e3ac1... Support extended fields for MP4 tags

(*) This commit already existed in another branch; no separate mail sent