Improved Bottom Input

The current state of the bottom input is cutting off the SelectionBorder in OSX 10.9.4:

![screenshot-1](https://cloud.githubusercontent.com/assets/275617/3459585/4dceb600-020e-11e4-8e7a-e68fccec90fe.png)

These commits update the display to center it better and remove the cutoff:

![screenshot-2](https://cloud.githubusercontent.com/assets/275617/3459590/614ef384-020e-11e4-8002-d60166aa50e8.png)