Finished init methods for commit, note, namespace, and project.
Init methods are finished for diff, issue, and milestone.
Added isEqual, hash, and description methods to all the models.
Merge branch 'jeff-dev'
Merge branch 'jeff-dev' of github.com:Indatus/objc-gitlab-api into jon-dev
Merge branch 'jeff-dev'

Conflicts:
	objc gitlab api/models/GLUser.m
add json init protocol
add protocol compliance to models
add method stubs for request project data