Fix. DONT_DESTROY and MORE flags has same value.
Add. `init_socket` function create socket based on socket handle.
Add. `skt:handle` returns socket handle.

```
shandle = skt:handle()

-- create socket based on handle
skt =  zmq.init_socket(shandle)
```
Merge branch 'master' of https://github.com/moteus/lzmq