issue 960, 772, 946 ChildModel, clonedModel

not using repaint seems to save issue #960

@aesnyder 

Commits deal with 2 issues

1. Google Chrome Painting which appears to have been caused by changes originally made by 772 fixes. 

2. Model Changes via reference and by value (cloned). Cloned for comparisons to do dirty checks to figure out updates. The reference is for the front end controllers to be able to make changes and then have them reflected back to the directive.
need to revert this is a typo from a different approach to fix the meximarkers / windows race.