Bug: proxy toString() produces NPE

[kabl]

If you call the "toString()" method of your proxy this will produce an NPE.

proxy = ethereum.createContractProxy(...)
proxy.toString(); // <- NPE

This behaviour is also in other Object methods. Like "hashCode()" and "equals(...)".

The problem is that the method "SmartContract.callConstFunction(...)" tries to map the method name "toString" to a method in the Smart Contract Interface. Which does not exists.