Add samsung air conditioner support

 * Login
 * Get token
 * 1x minor extra callback in the core device API, to mimic the 'first discovery' behaviour
 * Set temperature implemented, with bounds (16-30 degrees C)
 * Basic status (reset or present) implemented

Right now the UI is still in F, and the fan controls, timer controls don't work.

Additionally, the .alert() behaviour is untested, so I was still needing to view the console to know about the first-login-get-token requirements, and run to the AC.
However, it should be possible to retry ```setup()``` at any time.


Sorry about the messy change history as well - I can redo this as a cleaner diff if wanted.