allow distinct black and white options

[borg323]

Can be used with e.g. --white.cpuct=1.5 or --black.fpu-value=0.5.
Works for most all options except time manager, backend, network, logfile, syzygy path, cache size and strict uci timing but not all edge cases are handled.
Only works on the command line , and any value set takes precedence over the equivalent uci option.