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
Capitalizing `unittest-cov` just looks ugly.
Also the names are pretty long and arch isn't changeable, how about omitting it?

```
DUB build debug
DUB build release
```