oh silly me, actually TokenTypeJ can be in Scala
insert a new phase Namer0 before StructureParser

initially it just contains Keywords and Constants, relocated forward
from Tokenizer. perhaps later more parts of Namer can migrate back
into Namer0.

rationale: the fact that certain identifiers are special isn't
properly part of the lexical syntax of NetLogo. they aren't lexically
special; their specialness comes later, once we're parsing.  so let's
keep it out of the lex package
major overhaul of Namer

replacing a mass of intertwined, ad hoc code with something that has
some order and structure.  I spent a long time on this.
split off ParserExtras from Parser