changed: Properly exit screensaver on shutdown (fixes #16028)

[arnova]

Ideally we should abort any Python (addon) script before we start shutting down, but some skins (why?) rely on some addons, so (for now?) let's at least properly shutdown the screensaver. This also partially fixes the crash in ticket #16028.

[MartijnKaijser]

i guess it makes sense to wake from screensaver before shutting down

[MartijnKaijser]

@jimfcarroll any suggestions about the python add-ons?

[arnova]

Note that this does NOT fully fix ticket #16028, it just makes the race causing the crash less likely.

[jimfcarroll]

The python script shutdown doesn't take into account order or dependency. I'm not sure how to resolve this. Perhaps we could add a reference counting mechanism.

[arnova]

@jimfcarroll : You mean that instead of shutting down all scripts after the skin is unloaded, just unload the ones of which we know they are actually not used anymore? Another idea could be simply flagging them as such simply with a boolean in the addon object we can set/check, and unload everything before the skin unload that doesn't have that flag set? Perhaps we should continue this discussion in http://trac.kodi.tv/ticket/16028 ?

I think we should merge this PR anyway as that's a separate issue.

[MartijnKaijser]

just to be sure
jenkins build this please