Removed redundant/unused conversions.
Documented all of the conversions, and renamed them to pack/unpackX, to match the API spec.
Updated/added some tests in AC35UnitConverterTest.
RaceStatus now contains a Bearing instead of a packed int bearing.
RaceStatus now contains wind speed in knots, instead of MMperSec packed.
This means that only RaceStatus decoder/encoder need to care about the bits-over-wire packed values.
issue #35#36
#story[1095]