checkpoint on Parser work
wip adding callbacks to parser
Parser can not send callbacks after identifying some input
started on CSVParser; however it has highlighted that the callbacks are not being uniformly applied.  Adjusted the post process callback as stack frames are popped, but am planning a wider refactoring to reduce the number of edge cases in the current implementation
minor reordering of code in Parser.java to aid reading
duplicated LabelNode to CharacterNode and brought it up to the same point; the next steps are to extend it to take payloads and be nestable
-a
promoted trie to a general collection in mosaic-lang; also started to deprecate mosaic-collections and move the useful stuff into mosaic-lang
ported GraphBuilder over to mosaic-lang and renamed to TrieBuilder
renamed TriBuilder to TrieBuilderOp and created TrieBuilders