Hotfix on doubly linked list that was leaking memory (and somehow wasn't messing tests)
Added abstract class for trees
Basic implementation of AVL-balanced tree. Somehow I'm getting segfault and the big piece of shit called Eclipse, instead of giving me a hand on debugging, is pulling me towards lava. I'll try to debug better at the lab tomorrow.
The segfaults of c7858a0d8278625c0338f335de64c7181edd8b27 were caused by swapping left with right on rotating methods. I feel so Aldo right now.
Created AVL-tree removal, deletion and copy-construction. Removed unneeded node destructor. Fixed mistake with pre- and post-order listing.
Added comments to the AVL-tree. It is now stable, tested and leak-free.
Merge pull request #2 from ranisalt/binary_search_tree

Binary search tree is ready