gtk: Allow pasting using the mouse.
* gtk+-2/gtksecentry.h (_GtkSecureEntry): Add fields insert_pos, real_changed, cand change_count. (_GtkSecureEntryClass): Add field paste_clipboard. * gtk+-2/gtksecentry.c (PASTE_CLIPBOARD): New. (gtk_secure_entry_class_init): Set paste_clipboard and create paste-clipboard signal. (gtk_secure_entry_button_press): Call gtk_secure_entry_pase. (begin_change, end_change, emit_changed): New. (gtk_secure_entry_real_insert_text): Use emit_changed. (gtk_secure_entry_real_delete_text): Ditto. (paste_received, gtk_secure_entry_paste) (gtk_secure_entry_paste_clipboard): New.
The new code as been taken from gtk 2.20.1.
I have not figured out why the keybindings for C-v and s-Insert do not
work.