Change Return Type Signature of Process Methods

The method signature of TProcessor and TAsyncProcessor is:

public boolean process(...) throws TException;

It's not clear what the return value here because there is no documentation, but parts of the code do not even bother checking the return value. All of the returns, save one, are hard-coded to true. If there is a problem, code should throw an Exception. Make this a void method.

Note: This the method signature in other languages is also a boolean.