test_git: Fix the name description of CommitCreateTests().
git: Make 'hash' a property.
docs: Add viewer.git.rst.
git: Add documentation to VALID_HASH_LENGTH and VALID_HASH_CHARACTERS.
docs: Generate documentation for __init__() methods in the git module.
git: Add a proper sphinx documentation for Commit.
git: Add a proper sphinx documentation for Branch.
git: Remove useless :py domain qualifications in the docs.
git: Add a proper sphinx documentation for Git.