After delete, record point location in undo.

After delete, record point location in undo.

Addresses Bug #21968.

	* lisp/simple.el (undo-auto--add-boundary): Clean up code to
	better support intercalating calls.
	* src/keyboard.c,src/keyboard.h (command_loop_1): Store value of
	point and current buffer before each command.
	* src/undo.c (record_point): Now only record the point.
	* src/undo.c (prepare_record): Functionality removed form
	record_point.
	* src/undo.c (record_delete): Check if point needs recording.
	* src/undo.c (undo-boundary): Record value of point before each
	boundary.
	* test/automated/simple-test.el: New tests.

Conflicts:
	src/undo.c