Add hasattr guard around "pinger.close"
Don't choke if intermediate results dir already exists
Minor typo
Move mkdir_p to convenience library
Fix copyright
Fork for every replay of MCS (untested)
Merge branch 'master' of github.com:ucb-sts/sts into migration_bug

Conflicts:
	sts/control_flow/mcs_finder.py
	sts/util/convenience.py