Added tag command support, formatted code to facilitate addition of more Git commands in the future
Added a bit of error handling
Fixed error handling
Removed 'white' setting from jshint rc file as it causes errors for an indented switch statement, moved error handling to util function
Merge branch 'tag-support' of git://github.com/jrolfs/grunt-git into jrolfs-tag-support

Conflicts:
	tasks/git.js