New "stylish" skin for Krumo.

Hi, 

I'm working on a new theme for Krumo. See the screenshot below for how it looks. Note that all these changes are made in CSS only. 
Next up, i'd like to tweak the HTML output, to make it a bit more modern and easier to read. 

![screen shot 2013-10-29 at 13 18 59](https://f.cloud.github.com/assets/1833361/1427838/a8768394-4094-11e3-8c47-a61b9021acee.png)