add support for groovy

add support for groovy

groovy is an abject-oriented language alternative for Java platform.  for code highlighting sake, the language is similar so I just added the groovy file extensions to the java list.  screenshot of test included.

![image](https://f.cloud.github.com/assets/166513/2387380/463e1506-a936-11e3-9f32-ac54aaa5cfde.png)