New, much faster implementation of a FIT parser in C#.

Revision 0.3.0

• Added declarations for all of the field types and messages that are a) generated by my Garmin 800 and b) defined in the SDK. There are some undefined records and fields that are generated by the Garmin 800, but which aren't defined in the ANT+ SDK.

• Breaking changes happen here. The major one is building a reflection-like mechanism to dump the schema of .fit files for inspection. This requires looking up fields by field number, which couldn't really be done effectively using enums. I switched to a system of static fields in static classes that give similar results to enums, but which also allow me to add some additional data to each field declaration such as whether it is an enum or not.