Renamed http_parser functions to avoid symbol conflicts with nodejs.

Change-Id: I14607d6e451e3d430b639b3da8dd9530482ee8f8
Reviewed-on: http://review.couchbase.org/30117
Reviewed-by: Mark Nunberg <mnunberg@haskalah.org>
Tested-by: Brett Lawson <brett19@gmail.com>