Performance optimizations

[breznak]

As an alternative way of optimization, I came up with

Implement SpatialPooler with Connections backend

The idea is to ditch separate code for SP, and use just the TM. In reality, bioligically the two processes (SP, TM) are not separate. In code, TM uses Connections class; SP has the logic in itself. SP works as TM that has only 1 cell per column (no high-order memory). WAYs to do it: A) instead of SP, call TM(with 1 cellPerCol) will need to implement inhibition. B) keep SP code, just also use Connections as the backend PROs: code cleanup more biological possible better optimizations C…