Avoid subprocess call for repository initialization.
Repo.branch(): Default to repo HEAD if no commit_sha was specified.
Simplify staging by calling out to dulwich convenience function.

Fixes some tests.
Cope with changes in branch_list() API
Pass DIR to Repo.status, as it is now mandatory.
Merge pull request #39 from jelmer/fix-gittyup-tests

Fix gittyup tests.
Merge pull request #46 from primaryobjects/master

Username/Password Prompt for Clone, Push, Pull
#34 Python 3/gedit 3.8+
Use dulwich.porcelain.tag for tagging.
Use dulwich.config.ConfigFile.
Remove custom config parser - call out to standard parser in dulwich instead.
Require newer version of Dulwich.
Simplify tag_list function.
Simplify Repo.commit by calling out to Dulwich.
Remove unused _get_config_user helper.
Remove unused exceptions.
Remove unused _get_working_tree.
Ignore some generated files.
Avoid accessing private member variable of Index when removing entries.
Merge pull request #48 from jelmer/ignore

Ignore some generated files.