resolves #141: git ship open changes error message
resolve #150: optimize git-ship checkouts
refactor: Separate git-hack features
resolves #128: Fix extract bug
More rounded out command description
ShellCheck linter
Fix lint errors
Merge branch 'master' into kg-shellcheck-travis

Conflicts:
	bin/lint
	git-hack
	git-ship
	helpers/git_helpers.sh