Added alias for grabbing the date of a commit

Useful since the format string isn't the easiest thing to type in (or
remember).
Alphabetized git aliases

... for readability!
Removed a few old and unused git aliases
Removed git alias to make a pull request

GitHub does a good job nowadays with prompting you to make a pull req
for recently pushed branches.
Removed git alias to fetch a pull request

The addrefspr alias that adds pull requests as local refs is a much
nicer way of handling this.
Updated git tar alias to be more automatic and more useful
Added vim alias to quickly update a diff
Updated Salt instantiation to discern master/minion opts