Add optional wake on lan support

[puenktchen]

Hi @margro as you can imagine, not everyone has a tv server that's online 24/7.
But sometimes a user just wants to use Kodi only for file playback or legal streaming content. If right at this time the tv server isn't reachable, your plugin puts itself in some kind of deactivated state. If after file playback the user wants to watch tv, he has to start his tv server and also has to restart Kodi. Very uncomfortable!

Kodi's internal wake on lan doesn't work for pvr. The Advanced WOL addon doesn't work reliable on Android devices, because it can't query if the server is online already.

So here's the request: Please add wake on lan support to your great plugin.
There should be two options for this. One main option that wakes up the server with every request, also when epg updates occur. And a suboption that wakes up the server only by a playback attempt.

Thanks in advance!

[B0ycee]

+1 for this enhancement

Would be good if it is possible to implement independently of (i.e without depending on) Kodi's built in WOL function (https://kodi.wiki/view/List_of_built-in_functions) as this has significant limitations in that it can only wake a server on the same subnet (using broadcast address 255.255.255.255). I actually tried to open an issue with Kodi for this limitation, but seems it has been closed (xbmc/xbmc#16966). Using the IP/hostname already captured by the plugin (+ addition of MAC address) it should be possible to generate a wake packet regardless of whether server if local subnet or remote.