Java nonblocking server with more than one thread for select and handling IO

I've used the HsHa server model to write a server that uses a thread for accept and a separate, configurable number of Selector threads to handle IO. I'd like to contribute this back to Thrift.

For apps that are RPC-heavy and require little computation from the executor pool running on multi-core architectures, this server allows gets throughput as IO is not limited by one CPU.

Please take a look at the attached patch.