Visual feedback

Append a `^C` when the command is interrupted.

Output lines now line up right with each other (like a normal terminal). Added a container around this to keep it clean.

Let me know if the padding or margins need adjusting.

Demo:

![beautify](https://f.cloud.github.com/assets/836375/2339962/83fb4ed2-a4bc-11e3-9e17-f5e214f2186f.gif)