This adds Sha224, Sha256, Sha384, and Sha512 enum values to
QCryptographicHash::Algorithm. The implementation comes from RFC 6234,
http://tools.ietf.org/html/rfc6234, which is added to
src/3rdparty/rfc6234. Only the headers and SHA-2 code is included in
src/3rdparty/rfc6234 (the SHA1, HMAC, and HKDF code is not included).
Change-Id: I85139fd118291f15efc22899a5ddd1cc83810cfb
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>