This affects both the BlockChain/GetBlockHeaderReply and the
BlockChain/GetBlockVerboseReply calls.
The field with id 75 was confusingly called 'bits', but this is really
the blocktarget from the blockheaders. We renamed this.
This field is a int-encoded-floating point value and as such it makes no
sense to send it as a simple int. It is now a byte-array.
Notice that the documentation always listed it as a byte-array so we
actually fixed the implementation to follow the spec.
tomFlowee
a674a3fb7c