Use lua-http-parser to parse requests

[moteus]

I rewrite Request class to use lua-http-parser library.
I do not make PR because it require library with this PR.
You can checkout http_parser branch in my fork.
Library itself has no external deps and insatlls on Windows/Linux without problem.
Currently I rewrite Request class.

• Handle timeouts. methods like :method(), :path(), :receiveBody() returns nil and timeout so it possible call them again.
• After all data readed all methods returns nil and closed and do not read and data from socket.
  So in theory it possible implement keep alive feature.
• Support Transfer-Encoding: chunked body.

If there interest to add it to main repo please let me know. It original lua-http-parser will not updated it
will be possible create fork of it or even add it inside repo itself as external deps (not good idea though :) )

Update
To install can be used now

luarocks install pegasus http.parser --server=http://luarocks.org/manifests/moteus