[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.


However, this might be a candidate for CoffeeScript since this may need to be customized further. One thing to consider is PropMap is O(1) with a worst case of O(n) when needing to iterate (PropMap.values and .keys). You have a lot of Binary Tree stuff which I assume is advantageous for sorting markers which are close. So would it be advantageous to use PropMap for cases you know the marker key upfront. I'll have to find some code in the NgMap marker clusterer that took advantage of this. (This could be a moot point, but just a thought.)