Adding some basic utilities
I have just added some basic utilities to check if it's android, iOS and mobile.  I love the project and just wanted to add the code i keep adding over and over and add a spot for more little helpful functions.  I also added constants to make it easier to do comparisons.
Merge pull request #11 from joeylgutierrez/feature/adding_utils

Adding some basic utilities
Merge branch 'master' of https://github.com/srfrnk/ng-device-detector into feature/updating_with_constants

Conflicts:
	ng-device-detector.js