Bugfix: hashbuster: Close device after failures
Bugfix: hashbusterusb: Close device after failures
Bugfix: twinfury: Avoid crashing when next_work is not populated here
Merge branch 'hashbuster' into bfgminer-3.10.x

Conflicts:
	driver-hashbuster.c
Merge commit '3369f44' into bfgminer-3.10.x
Merge commit 'dd882a1' into bfgminer-3.10.x