[gtk] (8 commits) Non-fast-forward update to branch wip/baedert/for-master

[Timm Bäder <baedert src gnome org>]

The branch 'wip/baedert/for-master' 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:

  3b1fe89... Add a gtk valgrind suppression file
  b5ed260... actionmuxer: Plug a memory leak
  92bd798... widget factory: Plug a memory leak
  3d63918... widget: Unref previous transform
  d68bb72... suppression file: Add rule for media extension gio modules
  a67ce43... transform: Fix identity transform fast paths
  52a85ff... iconhelper: Try to avoid some save/restore calls
  4713fba... gl renderer: Properly clean up program state transforms

Commits added to the branch:

  d1c37c4... Add a gtk valgrind suppression file
  4123c85... actionmuxer: Plug a memory leak
  1459ca2... widget factory: Plug a memory leak
  449c96f... widget: Unref previous transform
  dbc49e7... transform: Fix identity transform fast paths
  95f30fe... iconhelper: Try to avoid some save/restore calls
  b062594... gl renderer: Properly clean up program state transforms
  042f7d1... compare-render: Don't unref an invalid GFile