Minified compatible setup

Hi, 

I've changed to code in such a way that it is minified compatible with ngmin.
This code now works by default with a yeoman project.

In effect this means that I've rewritten the provider into a provider and a service part. 
Next to that I've added a bit of README to get a better idea on how to add the analytics. 

Thanks for building this stuff, works great and inclusion for the event reporting is perfect. 

I've tried this change with a project that worked with your version (0.2.3) and thereafter with these changes and there is no need to change the way it is added to someones' project. (maybe you can test that with another project)

Kind regards, 

Olger