KDEREVIEW: nowplaying dataengine and applet for plasma

[Alex Merry]

I'd like to move the nowplaying plasma dataengine and applet to extragear/plasma.

The "help" source provides exhaustive dataengine interface documentation.  I will put the documentation in the relevant place (techbase?) once there is a place for it.

There aren't any ebn issues.

All the strings in the applet are translatable.

Alex