api: allow -b <ip>, and set bind retry to 20sec

before, only -b <ip:port>, <port> or 0 (disable) was allowed

easier to set -b 0.0.0.0 with default port
solo: stop submit of solved blocs (stale work)

rejects in solo mode often means "generated block is stale" (see Debug.log)

Most of current wallets only reports "rejected" reason without explanations.

So prevent this common error,
you can turn off this gbt feature (height check) with --no-gbt option.
lyra2: make_uint2 and set pool difficulty
keccak uint2 optimisation for SM>3.0 (x11 +40KH/s)

based on djm34 keccak 256-bit changes, and keep SM3.0 compat

affect most other algos too (quark, nist5, x13...)
skein: uint2 optimisation with SM 3.0 compat (+15KH)

Thanks to sp and djm34 for this fast uint64 storage alternative
lyra2: add sm30 device compat (skein256)
Release final 1.5.1