[gtk] (11 commits) ...Merge branch 'wip/chergert/textundo' into 'master'

[Benjamin Otte <otte src gnome org>]

Summary of changes:

  5e34121... texthistory: add GtkTextHistory helper (*)
  15b3c0f... textview: add undo/redo support to GtkTextView (*)
  7587996... editable: add enable-undo property (*)
  7e77afe... entrybuffer: remove text in ::deleted-text default handler (*)
  fb4fbfb... text: add undo support to GtkText (*)
  6d193d7... gtk-demo: wrap text operations in irreversible actions (*)
  e93408e... gtk-demo: add an undo demo for GtkEntry (*)
  67c0f88... gtk-demo: add a demo for TextView undo/redo (*)
  dba9298... gtk-demo: set irreversable actions for textview demos (*)
  bfc1e77... migration: add GtkEntryBuffer::deleted-text to migration gu (*)
  accbfc0... Merge branch 'wip/chergert/textundo' into 'master'

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