[gtk] (10 commits) ...Merge branch 'gtk-demo-fixes' into 'master'

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  e6d3f3d... gtk-demo: Fix the application demo (*)
  65769fd... gtk-demo: Cosmetic fixes to the assistant demo (*)
  33716d1... gtk-demo: Cosmetic fixes to the dnd demo (*)
  db42c23... gtk-demo: Fix a crash in the font explorer demo (*)
  663fb93... gtk-demo: Fix font explore initial state (*)
  58bc945... paper dialog: Make this look less horrible (*)
  72932d2... cell renderer text: Fix this to work again (*)
  cc3ecac... cell renderer spin: Bring this back (*)
  9e3147f... treeview: Fix embedding cell renderers (*)
  3644d3a... Merge branch 'gtk-demo-fixes' into 'master'

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