set unity launcher icons with .gschema.override

Hi Dieter,

here is my fix for the gsettings bug. I reordered some apt-get installs, then create the 10_local-unity-launcher.gschema.override file with the pinned icons. Now the icons appear upon the first start of lightdm.
I just let a sleep 15 for the vboxadd-x11 setup call. I don't know if this is necessary. 

Stefan