HACKING: add one more rule, unnoticed until now
HACKING: add one more rule, unnoticed until now

It turns out all the Banshee codebase has explicit accessors, even
if `private` is normally the default when there is no accessor.

This rule will deter people from using new MonoDevelop's SourceAnalysis
facilities (or Resharper in the case of VS.NET) to cleanup code in an
incorrect way.

dufoli/banshee,arfbtwn/banshee,Carbenium/banshee,dufoli/banshee,GNOME/banshee,Carbenium/banshee,stsundermann/banshee,dufoli/banshee,arfbtwn/banshee,arfbtwn/banshee,GNOME/banshee,dufoli/banshee,babycaseny/banshee,babycaseny/banshee,stsundermann/banshee,stsundermann/banshee,stsundermann/banshee,ixfalia/banshee,Carbenium/banshee,arfbtwn/banshee,babycaseny/banshee,dufoli/banshee,Carbenium/banshee,ixfalia/banshee,arfbtwn/banshee,dufoli/banshee,ixfalia/banshee,dufoli/banshee,ixfalia/banshee,arfbtwn/banshee,arfbtwn/banshee,ixfalia/banshee,GNOME/banshee,GNOME/banshee,babycaseny/banshee,stsundermann/banshee,ixfalia/banshee,GNOME/banshee,babycaseny/banshee,Carbenium/banshee,GNOME/banshee,arfbtwn/banshee,GNOME/banshee,Carbenium/banshee,stsundermann/banshee,stsundermann/banshee,babycaseny/banshee,babycaseny/banshee,ixfalia/banshee,GNOME/banshee,stsundermann/banshee,ixfalia/banshee,dufoli/banshee,babycaseny/banshee