changed all set_var methods to var
initial state for enr fac rebuild
developed a standard init/clone test suite and applied it to the enr fac
applied standard testing to src facility
actually, I like how the SinkFac separated it into a separate test. did so with src and enr
methods->members
set up enrichment facility to be able to have tests change internal state
made the growth region use its friend class methods
added documentation and initial testing to the enr fac