Added binary set operations with join-based implementation
added Leftist_Heap
added invariant proofs to AA trees
tuned
added 1-2 brother trees
converted to cmp
added splay trees
tuned references
added red black trees --HG-- extra : rebase_source : 28e43c87d5eb14090fa401987d8131c2067f6ab7
New subdirectory for functional data structures