Thread history

I don't know about the Nene side of the code, but on the RougeDC side, Scarlet's gun is somewhat heavy on memory. IIRC it's partially because of it's folded single-tick pattern matching. I might look at some heap profiling to see exactly how the memory usage is broken down some time, but I'm pretty busy these days.

In general, I kind of wish Java allowed the security manager to deal with memory usage, because then the robocode engine could have a 'real' rule about memory use. Instead we're just kind of left with "not too much please".