Make devicenotifier "mostly" work

This makes the devicenotifier work, including showing removable devices,
changing the config, changing status accordingly, reacting on newly
plugged in and removed devices.

- plasmoid.configuration seems broken in the systray, hardcode and warn
for now
- add compactRepresentation Component
- use PlasmaCore.IconItem inside that
- wire up setPopupIconByName to this using a property

A few things need to be fixed elsewhere first, but this makes it mostly
functional, and is a nice step forward.

screenshot: http://i.imgur.com/EaAH5in.png

DIGEST:Make device notifier work in Plasma 2