Added title to IRootScopeService

There appears to be no documentation for $rootScope worth a damn but there's this: http://stackoverflow.com/a/13407227/761388
@johnnyreilly `$rootScope` doesn't have this built in. This example : http://stackoverflow.com/a/13407227/390330 is just adding to it just like you can add stuff to any dynamic JavaScript object. 

This extension to the interface should belong in *your* or any other project that extends $rootScope based on how *they* extend it. E.g. I put a bunch of stuff on `$rootScope` like *enums* to make it easier to use in the HTML. 

Note (since you asked for docs): $rootScope is *exactly* same as any scope. In fact any $scope is created using the `$new` member of the rootScope which simply sets up a prototype chain and therefore $scope has all the properties (on the prototype chain) of $rootScope. Really (and literally) `$scope` extends `$rootScope` but doesn't matter in the defs since by default they are equivalent.