[develop] Performance Improvements (Markers, MarkerClusterer Rewrite)

Performance tweaks via @ccg1415 and [Realmassive.com](https://www.realmassive.com/search/Austin+TX/Office)

You can see how much faster things are there for yourself.

- lazyUpdate map.coffee
- modelsByRef to disable equality checks
- marker managers improvements (MarkerClustererPlus dropped from google tools sdk)

This is to open up this major PR for discussion how to handle merging in these changes.


This will have to be reverted for a merge. This is even true if it goes to its own dedicated branch. I would prefer git to continue to be part of the managers. Not to mention FitHelper could be slapped onto Polylines, Polyline and others to fit to shapes.