Output script may be malformed

E.g. the following transaction has several "Unknown address"
entries:

https://www.biteasy.com/testnet/transactions/36f428e87328fc7553695ce3ab5098f3d5cafdde0db9349b585d379cca4eae25
Useful class to import
Confirmations must be calculated dynamically

Don't store confirmations into transaction metadata because they
depend on current network height, not the height at the time of
transaction registration.
Autosave wallet on metadata updates