Bug 894263 - Power saving mode should be disabled after switching to 'never'. r=alive

If the power saving mode was previously enabled and the user switches the "turn
on automatically" threshold to "never", the mode should be disabled, thus
ensuring that the functions previously disabled (i.e. Wi-Fi, Data, Geolocation,
Bluetooth) are enabled again.
Merge pull request #11077 from mcirlanaru/bug_894263

Bug 894263 - Power saving mode should be disabled after switching... r=@alivedise