Implementation of the Graph Store Protocol
Importing the graphstore protocol testcase

This is a copy of
http://www.w3.org/2009/sparql/docs/tests/data-sparql11/http-rdf-update/

The idea is to parse this HTML page and run the tests it contains.
Fixed w3c's testcase (hrmpf!)

Fixed missing Accept headers

Uncommented a wrong test:
This request should fail according to the testcase. To me and to my
implementation, this request looks perfectly valid.

Fixed relative URLs as path argument

Fixed response codes:
Changed several response codes. Mostly from 200 to 204 because there
is no response body.

Fixed bad turtle syntax

Added comments indicating the changes (look for 'rdflib').
Testcase parser for protocol tests

This parses all HTML files in test/endpoint_protocol and runs the
tests they contain.