Updated to AFNetworking 1.1.0
Converted to ARC, modern Obj-C syntax, new base64 function

Converted to ARC and modern Obj-C syntax. I also copied the base64 and
the AFPercentEscapedQueryStringPairMemberFromStringWithEncoding
functions from the AFNetworking project.
Bugfix, now it works with all OAuth providers

Hacked around a simple bug in
AFSignatureUsingMethodWithSignatureWithConsumerSecretAndRequestTokenSecr
et, the actual design of the class doesn't permitt a better solution :(
Updated example projects

Updated the example projects to ARC