Added PATCH description to the http-methods RDF

Dear Group,

Attached you find an updated version of the HTTP methods RDF schema.

Updates are:
-PATCH method (see ACTION-118: http://www.w3.org/WAI/ER/tracker/actions/118)
-adjustment of description sections to something more meaningful (used 
parts of http://www.rfc-editor.org/rfc/rfc2616.txt and 
http://www.rfc-editor.org/rfc/rfc5789.txt for that)

We have also the suggestion to change the reference url from the 
specifications to http://datatracker.ietf.org/doc/rfc2616/ and 
http://datatracker.ietf.org/doc/rfc5789/ from IETF instead of the urls 
from rfc-editor.org. If the group agrees we can apply these changes.

regards,
Philip

-- 
Philip Ackermann
   Fraunhofer Institute for Applied Information Technology FIT
   Web Compliance Center: http://webcc.fit.fraunhofer.de/
   Schloss Birlinghoven, D53757 Sankt Augustin (Germany)
   Tel: +49-2241-142639