#NO_ISSUE some refactorings
changes based on feedback
further refactoring of
Merge pull request #270 from drexin/wip-refactoring-drexin

#NO_ISSUE some refactorings
Added a dataTimeString property to the MarathonEvent object. This property is populated with the current date/time (UTC timezone) with ISO8601 formatting. Renamed FrameworkMessageEvent to MesosFrameworkMessageEvent to make it clear that this object is for the scheduler.