Moved no_fit definition into a separate file
created standalone file for no fit
Different approach to calculating fitness whereby the genotypes are pre-computed, and the union of all set bits is walked.  This requires that the bits to be disambiguated.  The assumption being that it is more efficient to walk a single block and disambiguate, than it is to walk multiple unambiguous blocks
Renamed test
Added bool for neutral state. Fixed additive fitness definitions
removed assert statement. Frequency of all impacted performance
Changed ostream operator definition to remove ref_count, and perform a bit_count
Modified logic for generating variable elements bit set. Fixed definition for updating free subset
Added ability to provide iterator for block of selected elements to be used for fitness computation
Added ability to reset an iterator. Initial callgrinds suggested frequent construction of iterator was a bottleneck
refactored log path of stats. Added custom generator for basic_allele. Changed how ALL_NEUTRAL_OPTIMIZATION is used. Fixed bug in fitness calculation
Cleaned up commented sections of code