Go: TDserializer is not resource pool friendly

Currently TSerializer is resource pool friendly (see here for an example), but TDeserializer is not. When putting a TDeserializer back into resource pool, some extra works need to be done:

defer func() {
	deserializer.Transport.(*thrift.TMemoryBuffer).Reset()
	deserializerPool.Put(deserializer)
}()

If we change the type of TDeserializer.Transport to *TMemoryBuffer, and also call Transport.Reset() at the beginning of Read and ReadString (we already do both in TSerializer), it will make it more resource pool friendly.

This will be a breaking change, though.