Payment channel API. Negotiation af the channel duration.
1. Client requests a time window, in seconds relative to now.
2. Server suggests an expire time, absolute time in seconds
3. Client accepts or rejects the servers proposal.
Note that the IPaymentChannelClient.ClinentConnection interface has a new method. This will break old implementations.
Let the client request the duration of a payment channel. Server can set allowed time window.
Fixed grammar
Always use position 0 for LocalTransactionSigner sig, we don't know in advance what position we'll end up in
Fix p2sh bloom filter construction
Proper signature insertion for P2SH scriptSig