Added mongoDB-esque theme

Separated the inline css into an external file for easier editing of
overall theme, as well as to include reference to banner image (which
was too large/complex to store as base64 data in php file).
Commit with current version of original authors code

Previous commit used older version. This version includes updated
elements in original authors code + my theming.
Merge pull request #13 from tveatch/master

Added mongo theming