added comments to hidden channel. still seems to get correct output; ws is still collected all in WS rule.  Doesn't emit comments.  line info now correct in INFO features.
added comments to hidden channel. still seems to get correct output; ws is still collected all in WS rule.  Doesn't emit comments.  line info now correct in INFO features.

antlr/codebuff,MorganZhang100/codebuff,antlr/codebuff,MorganZhang100/codebuff,antlr/codebuff