Implemented Deadline Timer and timer_test
Added LAN discovery timer
Messenger Timer
remember to call timer_poll
Merge remote-tracking branch 'upstream/master' into timer

Conflicts:
	core/Messenger.c
Resolve Merge Conflict
timer_new -> new_timer and timer_delete -> delete_timer to avoid name conflict
Removed core/Messenger.c.orig

Cleanup from merge conflict.
Portabily print out uint64_t using PRIu64
Merge pull request #441 from slvr/timer

Timer Subsystem