mus-go development roadmap

[ymz-ncnk]

At the moment, mus-go can be considered not only as a MUS format serializer, but also as a set of primitives for implementing other serialization formats. Actually this concept could be implemented in a different way:

1. The code generator must be written for the MUS format (it will use mus-go primitives).
2. mus-go should be removed from the mus-format and possibly renamed.
3. mus-go should be split into small modules to allow different code generators use only what they need.