Branch/app logger

Adds a logger behavior that can be added to any object.  

Test with: mars-game -> app-logger

Solves:
http://redmine.virtualworldframework.com/issues/3680
http://redmine.virtualworldframework.com/issues/3679


As is, it could be used as a behavior or a component.  I used node2, because we could have used the position and size properties.  This is probably not going to happen though.  There used to be a requirement for behaviors, but after digging around I don't know if that's the case or not.  At this point, this is working, and I don't see it causing any issues.