add support for new cryptocurrency

1.

Build a package in src/go, and write your code in it. You are supposed to define a struct that implements the interface CryptocoinHandler. You can find the interface definition in src/go/api.go. Configuration constants such as the urls of gateways should be defined in package src/go/config.

2.

Append a key-value pair of the cryptocoin name and its reg address/accouont pattern into RegExpmap in validAddress.go.

3.

Register new transaction handler in src/go/api.go. Insert the constructor of your transaction handler in the switch-case statement.