Review request: Container plasma applet

[Giulio Camuffo]

Hi!

I've added in kdereview/plasma/applets an applet i made recently. It is, as the name 
suggests, an applet that lets you contain and group other applets. You can put it on 
the desktop or on the panel and then drag other applets from the add applet widget 
inside it. it puts the applet in a grid layout and it uses a spacer like the one in 
the panel to tell you where the applet will be put if you release the mouse. Then you 
can move the applets inside the layout.
It supports the drop and creation of "icon"s plasmoid from the entries from kickoff 
too.
When you put it in the panel you can choose, through a check box in the configuration 
dialog if you want it to behave like a PopupApplet or like a simple Applet.

Currently it needs an icon, because the question mark you can see now if you use it 
as a PopupApplet isn't so cool. I searched through the icon chooser but I coul not 
find an icon that suited my taste.

This plasmoid solves requests like https://bugs.kde.org/show_bug.cgi?id=193015 and 
others i saw on the bug tracker and on the brainstorm.

Giulio.