Moved distrib output to distrib cpp file, removed output.* files that are now empty. Implemented computing bias in distrib

More bugfix in depths function, added function to popmap to find an individual's group and return an empty string if not in popmap

Implemented map function with parser table. Updated markers queue to store total number of retained markers

Currently: compute depth from markers present in all individual; processing not efficient, rewrite later

Added attributes for total number of individuals in popmap and in marker data from parsing depths table