T2730
As a prerequisite to deprecating BCH.Address.toHash160(), this diff implements a local swiss army knife version of toHash160() that converts ecash, etoken, bitcoincash and simpleledger addresses to hash160.
This is possible since all input addresses are decoded into an address hash prior to encoding into base 58, followed by conversion to the hash160 hex string.
Relies on the bs58 library (6KB).