Disable the preferences action while shooting

Changing the resolution or camera device while recording can lead to a
crash, so avoid the problem by disabling the preferences action whenever
the mode change actions are disabled. Fixes bug 670782.
Close the preferences if the action is disabled

When shooting, the preferences action is disabled. If the preferences
dialog is shown, the resolution and capture device can still be changed,
so hide the dialog when the preferences action is disabled.
Update NEWS for 3.9.92 release