initial interface for grcnf_minmean_std using clorefs

minor changes

makeclo interface working

grcnf_minmean_std typechecks

tidying up a bit

implemented min_first_loop and simplified

complete test of algorithm typechecks but doesn't compile

reorganized a bit

changed expvar to an abstract type, but this isn't quite working
Merge pull request #62 from bbarker/falcon_mindisj_almost_working

initial interface for grcnf_minmean_std using clorefs