[gtk] (20 commits) Non-fast-forward update to branch wip/chergert/textundo

[Christian Hergert <chergert src gnome org>]

The branch 'wip/chergert/textundo' 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:

  7cfda4e... texthistory: add GtkTextHistory helper
  b470ac8... textview: add undo/redo support to GtkTextView
  211c115... entrybuffer: remove text in ::deleted-text default handler
  289365d... text: add undo support to GtkText
  9ba2921... entry: allow disabling undo for GtkEntry
  1c4b0e3... gtk-demo: wrap text operations in irreversible actions
  0579f7b... gtk-demo: add an undo demo for GtkEntry
  02a5947... gtk-demo: add a demo for TextView undo/redo
  d29c209... gtk-demo: set irreversable actions for textview demos

Commits added to the branch:

  e79d585... gdkselectionoutputstream-x11: Fix a memory leak (*)
  44093f4... stack: return the stack page when adding a child, to ease s (*)
  3086715... Merge branch 'gtkstack-addnamed-return' into 'master' (*)
  5d07877... Merge branch 'wip/sadiq/fix-leak' into 'master' (*)
  427b5d1... Adwaita: radios & checkboxes styling updates (*)
  6e5da14... cell text: Handle new pango enum values (*)
  53c9eb5... Move the ifdef to the right spot (*)
  3bf9277... Revert "Adwaita: radios & checkboxes styling updates" (*)
  b5ed2d3... tests: Add label-sizing.ui to the XFAIL list (*)
  bbfa3f3... texthistory: add GtkTextHistory helper
  bd8a2e8... textview: add undo/redo support to GtkTextView
  c4263e2... editable: add enable-undo property
  c3efb84... entrybuffer: remove text in ::deleted-text default handler
  ea4e44a... text: add undo support to GtkText
  d9288f6... entry: allow disabling undo for GtkEntry
  454a7aa... gtk-demo: wrap text operations in irreversible actions
  a441e1c... gtk-demo: add an undo demo for GtkEntry
  ce0a9e2... gtk-demo: add a demo for TextView undo/redo
  9d35927... gtk-demo: set irreversable actions for textview demos
  afb23eb... migration: add GtkEntryBuffer::deleted-text to migration gu

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