fixed problem where session wouldn't terminate at night
delete stimulus file after a trial
converted polling loops to utils.wait(dur)
converted polling loops to utils.wait(dur)
Merge branch 'dev' of https://github.com/gentnerlab/pyoperant into dev

Conflicts:
	pyoperant/components.py
Merge remote-tracking branch 'origin/dev' into vogel

Conflicts:
	pyoperant/tricks/evidence_accum.py
remove reference to stim_string
Merge branch 'vogel' into shape