* intervals.c (split_interval_left, split_interval_right): Change

* intervals.c (split_interval_left, split_interval_right): Change
	OFFSET argument of these functions to be origin 0, not origin 1.
	This is what all the callers currently want.
	* intervals.c, textprop.c: All callers changed.

	* textprop.c (Ftext_property_not_all): Renamed from
	Ftext_property_all, and changed sense of return value, so that it
	returns useful information if not all characters have properties
	EQ to value.  Now all the existential and universal questions can
	be asked.

	* textprop.c (syms_of_textprop): Don't forget defsubr for
	Stext_property_all.

	* textprop.c (Ftext_property_any, Ftext_property_all): Use EQ to
	compare property values, not Fequal.

	* textprop.c (Ftext_property_any, Ftext_property_all): New
	functions, from David Gillespie.
	* intervals.h (Ftext_property_any, Ftext_property_all): Declare them.