Add mysensors tcp ethernet gateway (#1861)

* Bump version of pymysensors to 0.6, which includes the tcp gateway.
* Update requirements_all.txt.
* Replace CONF_PORT with CONF_DEVICE and ATTR_PORT with ATTR_DEVICE.
* Add tcp_port in config.
* Try to guess if tcp or serial gateway is configured, by validating
	device name as an ip address. If successful setup tcp gateway, if it
	fails, setup serial gateway.
* Update device_state_attributes to show correct device, ethernet or
	serial.

homeassistant/components/switch/mysensors.py

@@ -99,8 +99,13 @@ class MySensorsSwitch(SwitchDevice):
     @property
     def device_state_attributes(self):
         """Return device specific state attributes."""
+        address = getattr(self.gateway, 'server_address', None)
+        if address:
+            device = '{}:{}'.format(address[0], address[1])
+        else:
+            device = self.gateway.port
         attr = {
-            self.mysensors.ATTR_PORT: self.gateway.port,
+            self.mysensors.ATTR_DEVICE: device,
             self.mysensors.ATTR_NODE_ID: self.node_id,
             self.mysensors.ATTR_CHILD_ID: self.child_id,
             ATTR_BATTERY_LEVEL: self.battery_level,