Renaming current TrieSet to ReferenceTrieSet in order to make new space optimized version the default.
Fixing bug in generated code, where special compaction case was not adhered to.
Copying map to start as a template for specialized set implementation.
First draft of specialized set implementation.
Fixing two problems with replacement of map values.

* The writer now correctly updates the dynamic type.
* The hash collision node now replaces value as well.
Minor formatting.