Updated to conform to http_parser.rb 0.6.0.beta.2 and greater.

Now current with `0.6.0.beta.2` and greater, but will also be fine with `0.5.3` I would guess. 

Updated gemspec to call for the jRuby compatible http_parser.rb
Updated `Reel::Request::Parser` via `RequestMixins`

Removed the missing methods from `Reel::Request::Parser`
Updated `query_string` and `path` methods of `RequestMixin`

( made sure to invoke the existing `uri` method which ought to be an instance of `URI` after the first call to `uri` )