Added function to pull data from Yahoo! finance, FRED, and Ken French's website.
The goal is to make it easy to pull in data off the web from various different sources using the same consistent framework.

As an example:

from pandas.io.data import DataReader
gs = DataReader("GS", "yahoo")

looks good to me. I'm not up on my git-fu but in the future I think you should do stuff like this in a branch so I don't pull your merge commits into pandas master. I'm going to cherry-pick these commits and close the pull request
 OK wow git cherry-pick really doesn't like this. I'm still too new to git to know how best to do this. Pulling your branch makes the history look nasty so I'm just going to take your latest revision of that file and mark you as the author in a commit.
 Alright, I'm just a n00b. the commits go top to bottom above, I was cherry picking in the wrong order. I just pushed to master-- you'll probably want to reset to a state prior to your first change (git reset --hard commit-sha1) and then pull from wesm/master

sorry for all the spam
 Ha!  Thanks.

You're a n00b?  I just started really using git a week ago, so I think I have your thoroughly beat on that front.

Happy to do this however you see best in the future...I'll try to follow something like the scikit.learn guidelines (http://scikit-learn.sourceforge.net/dev/developers/index.html).  You might want to post something like that on the pandas docs eventually if more people start to meddle?
