Add Visual Studio 2012 (blue) theme

I made a new theme, inspired by the layout of Visual Studio 2012 (blue). Besides the editor I also changed the style of the left and right sidebar, the footer and the menus. I started with the existing Visual Studio theme, changed some values and added styles for the user interface.

![vs-2012-blue-2](https://cloud.githubusercontent.com/assets/4706418/2561031/2406b734-b7f7-11e3-9d40-ac266964d3a6.png)