Added SublimeText Project Generator

- Added generator to create project files for SublimeText
- Adds import folders to the project for navigating etc.
-  Generated project inlcudes build systems to invoke DUB build test or run from inside SublimeText

Usage
dub generate sublimetext
My test case looks more like this which sounds like what you are suggesting.
![image](https://cloud.githubusercontent.com/assets/785973/5433276/ec3579a6-8499-11e4-840d-2cc2b812bf51.png)
What would you prefer to Package.name?