Redesigned CForest to minimize changes to asymptotically optimal planner...

...s it uses. Fix bug in benchmarking that caused huge log files. Added option for tree pruning in RRT*
There should be no difference anymore with any decent compiler. I don't have any problem with pre increment in new code, but I'd prefer it if you wouldn't change this in existing code. Once your branch is merged, it'll be easier to see what has changed in RRTstar without any distracting changes.