Add shift-clicking to extend the selection. (Roughly based on patch from

Add shift-clicking to extend the selection. (Roughly based on patch from

Sat Mar  3 15:39:49 2001  Owen Taylor  <otaylor@redhat.com>

	* gtk/gtkentry.c (gtk_entry_button_press): Add shift-clicking
	to extend the selection. (Roughly based on patch
	from Jay Cox, #50939)

	* gtk/gtkentry.c (gtk_entry_button_press): Fix triple-clicking
	to properly handle previous GDK_BUTTON_PRESS.
	(Patch from Jay Cox, #50938)

	* gtk/gtkentry.c (gtk_entry_real_delete_text): Move the
	'\0' back along with the deleted text. (#51148)