Centered tables

Tables are finally centered thanks to the removal of an overlooked `display: inline-block;`. Some more cosmetic changes were added as well.

The problem of #84 where the bottom corners of tables whose last row has a white background still persists, so it is not something germane to this set of changes.

Some screenshots of the transition:

![Screen Shot 2013-01-01 at 13 41 52 ](https://f.cloud.github.com/assets/198682/37259/9f82ffb0-5418-11e2-8a32-244540bd794f.png)
![Screen Shot 2013-01-01 at 13 42 11 ](https://f.cloud.github.com/assets/198682/37260/a8dce954-5418-11e2-896c-8fb2e2f54711.png)
![Screen Shot 2013-01-01 at 14 40 29 ](https://f.cloud.github.com/assets/198682/37262/d84385e0-5418-11e2-8a86-27df65e9671f.png)