Implement input stream preprocessing
 Fix missing error on NULL in CommentEnd
Emit better (and the right number of) errors from char refs
Handle "doubleEscaped" tokenizer tests
Handle "initialStates" tokenizer tests
Fix tokenize-example error printing
Emit temporary buffer on EOF in raw end tag
Discard non-matching raw-end tags from tokenizer state
Better char ref errors
Flag an error for things that look like char refs but aren't
char_ref: Move type variable from fns to impl