A First step towards better syntax highlighting

This is the first stage of better syntax highlighting. It currently handles greying out blocks that are conditionally compiled out, multiline block comments and multiline strings, as well as highlighting of classes. Comments and criticisms welcome. 

Has not been testing on OS/X, but has been tested on Windows.

See below screenshot for an example: 

![image](https://cloud.githubusercontent.com/assets/1762752/4013831/7a2c0200-2a1a-11e4-86c4-d11886cad04a.png)

Create an active pattern for currentText.Substring(textOffset).StartsWith("#else") have the AP implement whats in the this.ScanPreProcessorElse method. etc etc