Valiant cleanup effort: regional prefetch, bulk property flush, smarter waiting and much more

As described in #8 - a large scale rework.

It is being used in production and appears to be at least as stable as the previous branch. 

This is as much as I'll be able to do for a while - hope you end up merging it though :)

I added some brief dev notes in the README that go over the basics. Enjoy!