screen: Always consider monitors with fullscreen windows "in-fullscreen"

Fullscreen windows look weird when they are overlapped by system chrome,
which currently happens when another window is stacked above. We used to
auto-minimize fullscreen windows in that case, which proved to be both
unreliable and unpopular. So instead, keep the system chrome hidden even
when the fullscreen window is not stacked at the top.

https://bugzilla.gnome.org/show_bug.cgi?id=693991
Bump version to 3.14.1

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