README: Update documentation for scan-serial
README: Remove incomplete and unnecessary list of ASIC/FPGA devices
Merge commit '237563b' into bfgminer

Conflicts:
	README
README: Bitstreams no longer included with BFGMiner source
Merge branch 'rm_bitstreams' into bfgminer
Merge branch 'uniscan2' into bfgminer