[gtk] (6 commits) Non-fast-forward update to branch file-filter2

[Matthias Clasen <matthiasc src gnome org>]

The branch 'file-filter2' 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:

  c795e11... filefilter: Drop GtkFileFilterFlags
  3e695dc... filefilter: Convert to a GtkFilter
  bca553e... Stop using gtk_file_filter_filter
  a777931... Drop gtk_file_filter_filter
  661d784... docs: Cleanups for the file filter docs

Commits added to the branch:

  2d8fddc... filefilter: Drop GtkFileFilterFlags
  be3449b... filefilter: Convert to a GtkFilter
  35988d6... Stop using gtk_file_filter_filter
  11dd602... Drop gtk_file_filter_filter
  286a00a... docs: Cleanups for the file filter docs
  5a2f791... filefilter: Cleanups and optimizations