bug/memoryleaks fixes, UCT now seems to work but orders are not issued properly

fixed only Attack now only targets enemies
renamed GameState::enqueueEffect() back to GameState::addEffect()
bugfix GameState::isTerminal()
bugfix GameState::addEffect()
NodeUCT is now destructed, much less memory leaks
PendingEffects don't contain any effects for offset 0 any more
added UCB evaluation heuristic function
added Action::clone()
merge

fixed Heuristic, it now compiles