Add syntax highlighting for JavaScript #336

I created syntax definitions for DocBlockr.

This is very basic, but it's a start. From here on you can use this as a template to add syntax definitions for all use cases. 

If you now go to View->Syntax, you will see `JavaScript DocBlockr` under `JavaScript`. Selecting `JavaScript DocBlockr` will give you javascript syntax with jsdoc tag highlighting. You can also configure `JavaScript DocBlockr` to be the default syntax for all .js files.

![image](https://cloud.githubusercontent.com/assets/6479817/5408246/3096459c-818b-11e4-9d0f-995a1b129594.png)

I also included the source .YAML-tmLanguage file which you can use to compile the .tmLanguage XML with the [AAAPackageDev](https://github.com/SublimeText/AAAPackageDev) plugin.