Bugfix: Restore 2-minutes-past-last-work wait before terminating unused stratum connections
RPC: Use struct timeval for mcast bind timer
Partial: Bugfix: Turn spidevc into lowl-spi to fix building the knc driver without the bitfury driver

Conflicts:
	Makefile.am
	configure.ac
	driver-bfx.c
Merge commit '18b6c38' into bfgminer-3.5.x
Merge commit '38f54e6' into bfgminer-3.5.x