Remove URLDecoder call from path parsing

This brings GET handling in line with PUT handling, to conform to http://tools.ietf.org/html/rfc3986#section-3.3

Most of what the URLDecoder call does is change "+" into "%20" which is clearly an error.

(Actually it also removes double-encodings, which though should not be there from the beginning: eg turns "%252B" into "%2B".)