Very early beginnings of memory map notification support.

Very early beginnings of memory map notification support.
2008-06-10  David Smith  <dsmith@redhat.com>

	* tapsets.cxx (utrace_derived_probe_group::emit_probe_decl):
	Initializes .vm_callback.

2008-06-10  David Smith  <dsmith@redhat.com>

	* task_finder.c (struct stap_task_finder_target): Added
	vm_callback public field.
	(stap_register_task_finder_target): Sets up .report_quiesce
	handler.
	(__stp_utrace_task_finder_target_quiesce): New function.