Merge lp://qastaging/~elementary-dev-community/audience/prevent-screen-timeout into lp://qastaging/~audience-members/audience/trunk

I would prefer if this was a build flag instead so this x dependency becomes optional

Yes, we want to avoid hard-dependency on X as we are slowly switching to wayland in the years to come.

On top of that, maybe that could be done at a gala level, I think we should disallow screen-timeout when a video player is launched/playing (but we can add this to audience for now).

this is definitely not the way to go,
the problem is in os level and should be fixed there
audience have done enough to signal inhibit to sessionmanager

maybe we should have a daemon equal to gnomepower or fix gnome power management to inhibit our lockscreen