Start on a more generic way of building visitors
Start on a more generic way of building visitors

Work on #6, adds a ReadDataVisitor class that has a function to
gather and set a ModelInput (ReadData + additional info) from a given
site with user specified cuts for mapping and base quality.

Plan is that we can then use this class to build different visitors that
suit a given job or experimental design

dwinter/accuMUlate,dwinter/accuMUlate,dwinter/accuMUlate