Removed commented out debug code

And fixed error message for transition application
Removed asserts from Variant class

Might re-add later.
Added pool allocator for transitions

Found a bottleneck in constructing new transitions, which required the
use of memory pools to fix.
Removed old unused include
Added memory pool allocator to rules

And made transitions implement them through FlowState, yielding much
better performance when dealing with rules with lots of transitions.