Split create-breakpoint! into make-breakpoint, register-breakpoint!.

Split create-breakpoint! into make-breakpoint, register-breakpoint!.
Rename breakpoint-delete! to delete-breakpoint!.

	* guile/scm-breakpoint.c (struct gdbscm_breakpoint_object): New members
	is_scheme_bkpt, spec.
	(bpscm_make_breakpoint_smob): Initialize new members.
	(gdbscm_create_breakpoint_x): Split into two ...
	(gdbscm_make_breakpoint, gdbscm_register_breakpoint_x): New functions.
	(bpscm_breakpoint_deleted): Reset breakpoint number and stop function.
	(scheme_function breakpoint_functions): Update.
	* guile/lib/gdb.scm: Delete create-breakpoint!.  Rename
	breakpoint-delete! to delete-breakpoint!.  Add make-breakpoint,
	register-breakpoint!.

	testsuite/
	* gdb.guile/scm-breakpoint.exp: Update.
	Add tests for breakpoint registration.

	doc/
	* guile.texi (Breakpoints In Guile): Update.