Initial fairly naive implementation of state similarity expansion priming
Made configurable:
1) Whether piece heuristics can be used
2) Whether state similarity expansion processing is enabled
3) Player name
Also added dump of the configuration options used to the log
Include state hashes within a Hamming distance of 1 in the neighbourhood for state similarity
Switch to using a selection amplifier rather than a score-pre-seeding for state similarity to avoid positive feedback effects
Changed default for disabling of state similarity processing to true prior to branch merge while still experimental