Move left/right and red/black specific code into respective enums
Set encoding to UTF-8
AbstractSortedTree: a base class for RB trees (sorted maps and sets)
Rename AbstractSortedTree to AbstractRedBlackTree
Remove unnecessary abstract methods
Add missing licenses
Initial PersistentSortedSet
Revisited HAMT: abstract trie algorithm for memory optimized set
New perf test results
Fix warnings
Red Black Tree iteration