avoid "levels is 0" warning if no kbd backlight present
remove "battery recall" logic

the database is outdated several years now and the whole interface is
removed from current UPower release anyway, so let's get rid of it in
m-p-m, too
port mate-power-manager to upower-0.99 API

fix mate-power-manager for current upower versions
Merge pull request #98 from seife/master

make m-p-m work with current upower-0.99