overhaul events subsystem: API changes, ghashtable split for reg/mem events, signal handler in example and various bugfixes and improvements
Switch reg/mem_access enums to bitfield typedefs
fix
before byte-level refactor
split reg and clear functions
Page-level memevents working again
byte-level events
byte-events cleanup
combine shutting_down flags
fix PR tester failure
change reg/mem_access types to enums