[Merge] lp:~khurshid-alam/unity-settings-daemon/fix-low-battery-notifications into lp:unity-settings-daemon

[Khurshid Alam]

This is part of upower .99 port of g-s-d, but most of the commits are not required for unity. So I cherry picked only the most commit since double check is happening here.
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https://code.launchpad.net/~khurshid-alam/unity-settings-daemon/fix-low-battery-notifications/+merge/369223
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