[gtk+] (10 commits) ...configure: define GTK+ version before AC_INIT

[Javier Jardón <jjardon src gnome org>]

Summary of changes:

  c295ab0... gtktbutton: Move public members to private structure (*)
  dec57f8... Create a private header to access some GtkButton variables (*)
  9fa0edd... gail: we cant access button->in_button directly now. (*)
  fb3429e... gtkcombobox: Do not access GtkEntry internals (*)
  8c941d2... Add _gtk_entry_get_im_context() internal accessor (*)
  f2abd65... gail: Use accessor functions to access GtkEntry (*)
  c4be956... gtkentry: move public members to private structure
  224ce2c... gtktreeview: Use accessor functions to access GtkTreeViewCo
  4e3db2e... gtkcombobox: Use accessor functions to access GtkTreeViewCo
  39f5740... configure: define GTK+ version before AC_INIT

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