Add out-of-the-box support for date formats used by HTTP/1.1
Add out-of-the-box support for date formats used by HTTP/1.1

Adds support for RFC 1123, RFC 850, and ANSI C asctime() date formats
Details: http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html#sec3.3.1

0xced/RKValueTransformers,RestKit/RKValueTransformers