Added firing of named events on the $rootScope based off each timer's interval

I'm using this to save documents and do other housekeeping periodically.

Maybe you can implement it better than I have but I think it is a pretty useful addition.

I created an example in the index file.

Thanks for sharing the directive - even with the changes I made for my situation, it saved me a lot of time not having to figure out the other stuff.

Cheers,
Timothy