Reinit caching_agent

[darrenks]

Caching agent is not recreated when a new level is selected or you die and start over.

This causes 2 problems
1 the state of the world as it was before is remembered (and if this is the wrong level that is bad)
2 cached moves are continued to be played

I don't know of a way to add this since it would need to be a binding from tileworld saying that a new level has been started

Note: if we want to remember previous attempts on a level, we only need to clear the move cache, and then we get the state of the level from previous attempt for free