lambert units
Add rules for loading regular gaussian grids (regular_gg).
Merge pull request #11 from bblay/lambert

lambert / stero units
Merge pull request #12 from ajdawson/regular_gg-grib

Add rules for loading regular gaussian grids (regular_gg).
Added variable resolution PP rules from #10.
Merge pull request #17 from pelson/variable_resolution_pp_rules

Added variable resoltion PP rules from #10.
Add missing HybridPressureFactory import.
Merge pull request #18 from ajdawson/hybrid-pressure-grib

Add missing HybridPressureFactory import.