Introduce --benchmark-intense option
benchmark-intense: Generate individual work items from 2D work (tests host CPU rate of work production)
benchmark-intense: Simulate 250 KB generation transaction
benchmark-intense: Update work every second
benchmark-intense: Detect stale results
benchmark-intense: benchmark_update_interval constant in code
benchmark: Detect duplicate shares within 5 minutes
Bugfix: Fix CPU miner benchmarking within benchmark-intense mode
Merge branch 'benchmark_intense' into bfgminer
Bugfix: Stable pool recovery: Only care if the pool is enabled
Bugfix: Recheck current_pool after calling pool_died
Merge commit 'f2702fb' into bfgminer

Conflicts:
	miner.c
Merge commit '57df860' into bfgminer
Initial version of coinbase checking function for GBT and stratum
Share pool coinbase check reaction code
Bugfix: Keep connection active for rejecting and misbehaving pools so we can detect when they recover
pool_check_coinbase: Avoid redisabling an already misbehaving pool
Pool option #skipcbcheck to disable new coinbase checks