Instrument port_command/2, port_command/3, port_control/3
Use --ignore-timeout flag for start_timer and send_after
Merge branch 'exits-timers-afters'

Conflicts:
	src/concuerror_rep.erl
	src/concuerror_sched.erl
Wait for uninstrumented messages to be processed
More dpor tests
Add exhaustive scheduling tests
Optimal DPOR