Bug fix 1209399

This is a fix to bug #1209399 (Regression on SHA-384 and SHA-512)

The SHA-2 modules lost the "block_size" attribute along the way.
As result, the HMAC wrongly assumes they all have block size
of 64 bytes instead of 128 bytes (for SHA-384 and -512).
This patch re-introduces the "block_size" attribute.

Since we are at it, this patch also adds test vectors for HMAC-RIPEMD160.