gtk: Make Escape key work.
* gtk+-2/pinentry-gtk-2.c: Include gdk/gdkkeysyms.h. (enter_callback): Pass confirm_value_t to button_clicked. (confirm_button_clicked): Use confirm_value_t cast. (cancel_callback): New. (create_window): Add accelerator for the Escape key.
Original patch slighty modified by wk.
- GnuPG-bug-id: T1453