lex/parse idents into dollarIdent,dotIdent,questionDotIdent,etc
lex/parse Call command, plus a func for evaluating quoted expressions
Renames: Value{List,Map}Node -> {List,Map}LiteralNode
(WIP) exec for "if", and data ref node evaluation
if/for control execs, w/ tests.  data ref evaluation workingish.
switch execution