Make structs comparable and showable
Add test fixtures
Add a generic conversion utility
Add GitError algebraic data type
Implement a data Reader utility
Add dummy date encoding
Implement some rudimentary user info parsing
Make ObjectHeader decodeable
Make sure ObjectId always has the hash version and the raw version
Update library to have the latest modules
Update commit unit tests
Simplify ObjectType
Make Commit own its data
Implement some rudimentary Commit decoding