Rember the user input that triggered the completion, add API to the

Rember the user input that triggered the completion, add API to the

	* gtk/gtkentry.c:
	* gtk/gtkentrycompletion.c:
	* gtk/gtkentrycompletion.h:
	* gtk/gtkentryprivate.h:

	Rember the user input that triggered the completion, add
	API to the retrieve it and reset the entry contents to it
	if the user cancels the tentative completion during
	the inline-selection.

svn path=/trunk/; revision=17666