* Add a light entity class per V_LIGHT, V_DIMMER, V_RGB and V_RGBW.
Make these classes inherit each other up to MySensorsLight class.
* Map the entity classes to their S_TYPE in a dict.
* Check if an entity class map or just an entity class have been passed
to pf_callback_factory before using the entity_class variable in
homeassistant/components/mysensors.py.
* Add rgb_hex_to_list function in homeassistant/util/color.py.
* Make light controllable independently with types V_LIGHT, V_DIMMER,
V_RGB and V_RGBW. V_RGBW is not implemented in the frontend yet.
* Add discovery for light platform.
* Add optimistic mode config setting for switch and light
to allow feedback state from actuator.
* Move S_LIGHT, V_LIGHT, V_STATUS types from switch to light platform.
* Change node update logging to debug from info level.
* Fix some inaccurate comments.
MartinHjelmare