Fix outstanding build issues and parser audit results

Fix outstanding build issues and parser audit results

* Give SBuf I/O buffer directly to Http1::RequestParser

* Redesign parser state engine to represent the current state
  being parsed instead of previous completed. This allows much
  more incremental resume of a parse and reliable consume() of
  the input buffer as sections complete instead of complex byte
  accounting outide the parser.

* Maintain an internal counter of bytes parsed and consumed by
  the parser instead of a buffer offset. This allows much more
  reliable positioning of the state/section boundaries.

* Remove erroneous fprintf debug left in previous commit.

* Redesign HttpRequestMethod constructor to drop end parameter.

* Redesign all parser unit tests. Marking RFC non-compliance
  for future fixing.