requestForUnspentOutputsWithAddresses fix

I was unable to fetch unspent outputs for multiple addresses with the latest xCode6-Beta3 because of the pipe char "|". I replaced it by the encoded form: "%7C" and voilà! 

Btw, thanks for this great lib! Can't wait to see the next features.
Merge branch 'patch-1' of https://github.com/madshell/CoreBitcoin