cointerra: Import driver from cgminer as-is

cgminer commit: a3e3957809e358aeb2872f56a8e48db6cfc94051
Build cointerra driver
cointerra: Replace reset semaphore with a simple notifier
cointerra: Remove nodev checks for now
Add api_add_int16 to API functions.
Provide a copy_work_noffset function for copying a work struct but changing its ntime.

Conflicts:
	cgminer.c
	miner.h
Export share_diff function and add flip12 macro
Provide a function to discard queued work based on age.
Export the flush_queue function for use by drivers.

Conflicts:
	miner.h
notifier_wait, notifier_wait_us, and notifier_reset functions
lowl-usb: Cleanup dead code
cointerra: Dirty BFGMiner port
cointerra: Wait for info packet on probe
cointerra: Divide up processors
cointerra: Cleanup debugging
rockminer: Limit even unsafe frequencies to 640 MHz, since above that overflows frequency bits and triggers fan control
Merge branch 'bfgminer' into cointerra (does not build)

Conflicts:
	miner.h
util: min macro
Store a reference timeval with ntime_roll_limits
work_{get,set}_ntime inline functions