Add example git workflows to the wiki
If any of the other pandas developers would like to give a quick rundown of their workflow when hacking on pandas that would be greatly appreciated. I'll do the same. Once the dust settles, I'll collect the workflows and create a new wiki page with this information.

FYI, I'm trying to highlight `git` usage here, so if there are any tricks you have up your sleeves don't hesitate to show them!

cc @nehalecky

My pandas workflow usually goes something like this:
1. Always use `virtualenvwrapper`. Period. Then I do `workon pandas`.
2. Depending on how much time I have I'll try to prioritize based on some combination of which issues are high-priority and those for which I see an easy fix and those that I think would be fun to work on.
3. Once I've selected an issue I'll start hacking on it. I usually _don't_ use any local branches unless I'm implementing something new and there's a bunch of things for that feature that can be worked on separately.
4. I use `git stash` **all the time**. In fact so much so that I have aliases for every `git stash` subcommand. Often times I'll get interrupted and I'll need to stash something so I do. I can then come back to it. If you end up accumulating a crap ton of stashes (which I do) then you can inspect them with `git stash list` followed by `git stash -p stash@{0}` or whatever stash number you want to see the diff of. I'll also occasionally prune the stash via visual inspection and/or my own memory of what's been merged recently or by comparison of stashes to `upstream/master`.
5. Two things that I use a lot are the command `git push -u origin $(git rev-parse --abbrev-ref HEAD)`. This pushes a remote branch with the same name as the one that I made locally to the `origin` remote (my fork). I have `git rev-parse --abbrev-ref HEAD` aliased to `gcb` which I remember as "git current branch". The other command I use is `hub pull-request -b pydata:master` which _automatically_ submits a PR. I can essentially push the remote and the PR in a single step on the command line without having to use the mouse. Pretty neat.
6. `git reflog` is great for those times when you accidentally type `git reset --hard` and you need to recover something.
7. Finally I'll rebase using `git rebase upstream/master` to pull in the latest from the `upstream` remote (which I have set to `http://github.com/pydata/pandas.git`)
8. Throughout the dev process I'm constantly doing `git fetch && git rebase upstream/master`, although recently I've toned that down a bit and I've started to just do it when I need to.
9. I also use `git log` all the time. Since the standard `git log` is a bit too verbose I use [scm_breeze](https://github.com/ndbroadbent/scm_breeze) and it has a gorgeous standard `git log` (as long as you've set `git config --global color.ui auto`!)
