Made nc4 file nc_classic_model
Ok now checking units to see if an axis is lat/lon/lev/time. Also determines level is it has positive attribute
Added test file
chenged level test on positive attribute to exists AND be either up or down
Merge remote-tracking branch 'devel/bug406_cdms2NC4_files_not_classic_release' into release
Merge remote-tracking branch 'devel/bug418_detect_latlon_based_on_units_release' into release