[gtk] (8 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:

  2e1d157... editable: add enable-undo property
  00614da... entrybuffer: remove text in ::deleted-text default handler
  1baee29... text: add undo support to GtkText
  8123e8c... gtk-demo: wrap text operations in irreversible actions
  05cbaaf... gtk-demo: add an undo demo for GtkEntry
  69ded53... gtk-demo: add a demo for TextView undo/redo
  12a9796... gtk-demo: set irreversable actions for textview demos
  c07eb61... migration: add GtkEntryBuffer::deleted-text to migration gu

Commits added to the branch:

  6977897... editable: add enable-undo property
  a2e29bf... entrybuffer: remove text in ::deleted-text default handler
  7f407b4... text: add undo support to GtkText
  2b73344... gtk-demo: wrap text operations in irreversible actions
  33e161a... gtk-demo: add an undo demo for GtkEntry
  f52d48e... gtk-demo: add a demo for TextView undo/redo
  a775dbc... gtk-demo: set irreversable actions for textview demos
  3b11722... migration: add GtkEntryBuffer::deleted-text to migration gu