[ThickClient] Keep a managed reference to the TaskStatusIcon
[ThickClient] Keep a managed reference to the TaskStatusIcon

If we don't keep a reference to the task status icon, it may get GC'ed
early. Should fix bug #629534.

stsundermann/banshee,lamalex/Banshee,lamalex/Banshee,stsundermann/banshee,ixfalia/banshee,dufoli/banshee,Dynalon/banshee-osx,Dynalon/banshee-osx,Dynalon/banshee-osx,Carbenium/banshee,Dynalon/banshee-osx,mono-soc-2011/banshee,dufoli/banshee,babycaseny/banshee,petejohanson/banshee,lamalex/Banshee,stsundermann/banshee,mono-soc-2011/banshee,arfbtwn/banshee,GNOME/banshee,ixfalia/banshee,Carbenium/banshee,arfbtwn/banshee,dufoli/banshee,GNOME/banshee,mono-soc-2011/banshee,dufoli/banshee,petejohanson/banshee,lamalex/Banshee,Dynalon/banshee-osx,arfbtwn/banshee,ixfalia/banshee,Dynalon/banshee-osx,Dynalon/banshee-osx,mono-soc-2011/banshee,ixfalia/banshee,babycaseny/banshee,dufoli/banshee,Carbenium/banshee,ixfalia/banshee,ixfalia/banshee,babycaseny/banshee,GNOME/banshee,GNOME/banshee,GNOME/banshee,dufoli/banshee,petejohanson/banshee,dufoli/banshee,lamalex/Banshee,ixfalia/banshee,arfbtwn/banshee,stsundermann/banshee,mono-soc-2011/banshee,Dynalon/banshee-osx,Carbenium/banshee,stsundermann/banshee,ixfalia/banshee,babycaseny/banshee,arfbtwn/banshee,babycaseny/banshee,Carbenium/banshee,babycaseny/banshee,dufoli/banshee,GNOME/banshee,arfbtwn/banshee,arfbtwn/banshee,petejohanson/banshee,Carbenium/banshee,GNOME/banshee,GNOME/banshee,mono-soc-2011/banshee,babycaseny/banshee,babycaseny/banshee,stsundermann/banshee,lamalex/Banshee,stsundermann/banshee,mono-soc-2011/banshee,stsundermann/banshee,arfbtwn/banshee,petejohanson/banshee,petejohanson/banshee