Grunt structure

This PR contains all the needed files to have a grunt managed project (gruntfile + package.json for dev dependencies).
It also contains the needed file to publish on bower (bower.json) which will quickly be needed to deploy this Angular module into an app =)
The grunt process is quite simple for now :
- it takes files into src (multiple files to ease development as the module will grow), concat them into dist
- it uglify the concated file into dist
Of course, before uglification, angular dependencies are annoted.
Into dist, you will ultimately find the result project, the module you'll import into an app : clean file (useful for debug) or minified (useful for live).
The test part still needs to be defined (karma ? jasmine ? nodeunit ?)