common

This change set makes the orderer include the:
- Last config block
- Consensus metadata

In the same value that is used as the block signature value,
and this way it paves a way for orderers to be able to sign
both the block and the last config and the consensus metadata
in one signature invocation.

Change-Id: If5f331a7f7e859251af221937f2a3259e615369f
Signed-off-by: yacovm <yacovm@il.ibm.com>