This change set adds support for hash chain validation in presense
of configuration blocks that are found inside the block batches
being validated.

This is important because if a config block alters the validation rules
inside a batch, then validating the signature/certificates of the last
block in the batch needs to take into account the config block updates
themselves.

Change-Id: I03ef2a268ddc9ff63755d3a878f77d4814c5279d
Signed-off-by: yacovm <yacovm@il.ibm.com>