Add Name, GetNetwork() fns to Network
Add Spendable convenience fn to tx.Outputs list class

Makes it easier to iterate over usable outputs with foreach, while still preserving/providing the index of the txout in Outputs[]
default ctor for ColoredCoin, TransactionBuilder.FindCoin public
coinprism fix : using AssetId instead of old asset address, 1.0.6.6
Make Encoders singletons
Merge pull request #46 from dthorpe/TxOutList_spendable

Add Spendable convenience fn to tx.Outputs list class
Merge pull request #44 from dthorpe/getnetwork

Add Name, GetNetwork() fns to Network
Renaming IndexedTxOut, get rid of useless interface
TransactionBuilder guarantee that coins are not duplicated,1.0.6.7
TransactionBuilder.EstimateSize/Fees, 1.0.6.8