Added Fieldsfile boundary compression support (aka LBC).
Review actions and FF LBC loading test.
Added northwards test for LBC.
Merge pull request #831 from pelson/lbc_compressed_data

Added Fieldsfile boundary compression support (aka LBC).
ENH: FF Type 6 staggered grid support added.

This commit adds support for Arakawa type C grids with v at the poles.