r3043: Use binding strings for specifying endpoints. The property for

r3043: Use binding strings for specifying endpoints. The property for
specifying a endpoint is now also 'endpoint' instead of 'endpoints'. The
default endpoint (if none is specified) is still "ncacn_np:[\\pipe\\ifacename]",
where ifacename is the name of the interface.

Examples:

[
  uuid(60a15ec5-4de8-11d7-a637-005056a20182),
  endpoint("ncacn_np:[\\pipe\\rpcecho]", "ncacn_ip_tcp:")
]
interface rpcecho
{
	void dummy();
}

dcerpc_binding is now converted to ep_description in the server, but I hope to
completely eliminate ep_description later on.

The eventual goal of all these changes is to make it easier to add
 transports as I'm going to add support for
 ncalrpc (local RPC over named pipes) and ncacn_unix_stream (Unix sockets).