osgb 0.2 Beta

Initial release.

Changelog

Currently, "round-tripping" an OS reference to a lon-lat and then converting it back results in the loss of about a metre of accuracy. This is regarded as acceptable, but does result in two of the built-in tests failing due to a single meter discrepancy. There has been a report of much greater errors, but without more details from the bug reporter I have been unable to track it down.