base
added git grammar
basic functionality implmented for add, commit, checkout, push, status, and log
removed unused configuration file
removed unused git_context variable
updated parse tree traversal method.
added git branch command to git grammar.  made command options configurable via grammar config.  flake8 style updates
Merge branch 'git-grammar' of github.com:mzizzi/aenea-grammars into git-grammar

Conflicts:
	_git/_git.py
bugfix: added missing spaces to end of all git branch options.
improvement: added git pull command
Merge pull request #2 from mzizzi/git-grammar

git grammar