Ability to create Haxe sockets from NDLL calls in Haxe 3.3.0rc1

I'm working on a PostgreSQL driver NDLL that needs to get the socket from the database connection through the Postgres libpq API call and pass it into the Haxe code to use later in Poll.poll() calls.

In Haxe 3.3.0rc1 all socket NDLL code was reworked to use NativeSocket class and currently there is no way to create a new Haxe socket from a given low-level socket integer. The solution for this was proposed by Hugh in the mailing list: adding "socket_create(Int):Dynamic" and "socket_get(Dynamic):Int" to NativeSocket.