0.30 beta

1. Added b-tree CPU cache conscious optimization
similar to optimization described here
http://ftp.cse.buffalo.edu/users/azhang/disc/disc01/cd1/out/papers/sigmod/p475-rao/p475-rao.pdf
just a lot simpler, 20% random read rate improvement on loads exceeding CPU cache size

2. Made Predictive hash, lock free on reads

3. Added back test code

Fixes:

1. Fix B-tree erase issues
2. Fix B-tree bulk load sorting optimization