Add noninteraction parameter to ga.js event tracking
Add noninteraction parameter to ga.js event tracking

* The older version of track event has an optional boolean parameter
called 'noninteraction' that is provided for determining if the event is
considered counted as an interaction for bounce rate. By default this
value is false, as per the ga.js spec, which infers the event is counted
as an interaction.
* Also added missing method headers for _trackEvent and _trackPage.

revolunet/angular-google-analytics,mrcoleman/angular-google-analytics,Toxantron/angular-google-analytics