Plain Text signature is UrlEncoded twice

[bittercoder]

The PlainTextSignatureImplementation does an UriUtility.UrlEncode(..) for the signature. But the UriEncode.UrlEncode(..) is also called when adding the information to the header of the request.

Logged by: http://code.google.com/u/aritmeester/

Originally logged here:

http://code.google.com/p/devdefined-tools/issues/detail?id=6