TProcessor::process never returns false

The signature of TProcessor::process is

  virtual bool process(boost::shared_ptr<protocol::TProtocol> in,
                       boost::shared_ptr<protocol::TProtocol> out,
                       void* connectionContext) = 0;

Presumably, the return value is supposed to indicate success or failure. Unfortunately the generated C++ code always returns true, even when there are errors. For instance, if an RPC call is received but no matching function exists, we return a TException in the response but the 'process' method still returns true.

The attached patch makes the return values useful.