[CSS21] minor issue: location of comment tokens

btw:

4.1.1 Tokenization
COMMENT tokens do not occur in the grammar (to keep it readable), but any 
number of these tokens may appear anywhere between other tokens.

G.2 Lexical scanner
...
"!"({w}|{comment})*{I}{M}{P}{O}{R}{T}{A}{N}{T}	{return IMPORTANT_SYM;}

yet another exception?