Do not output a hash if the body_len is 0
Added the ability to modify what ports to process http traffic on.
Fixes #22
Documentation for the http module, outling usage and output format
Update help string for module http and update docs
Re-write of http_extractor for ChopShop v4. Utilizes parent http module to process http data

Invocation looks like: chopshop "http | http_extractor"