Bar plots are misaligned by default
There has been a recent change in bar plot default behavior that is causing misalignment of the bars on the y-axis. I'm not sure when this change occurred, but I will estimate 3-4 months ago. 

Previously, bar plots looked like this:

![good bar plot](http://d.pr/i/c2mO+)

However, the same code under '0.14.0-205-gbbde837' yields the following (ignore the theme differences):

![bad bar plot](http://d.pr/i/uoOf+)

So, the bars are bizarrely pushed to the right. Is matplotlib to blame for this (running 1.4.x)? 

Running Python 2.7.6 (homebrew) on OS X 10.9.3.
