[ServiceLocator] Using Current from AddOnProvidedServiceLocator now returns root application container instead of exploding
- .BeginLifetimeScope(SPFeature) also now supports usage in SPWebApplication and SPFarm contexts.
- More comments as well to thoroughly explain the PropertyBag inspection routine used to disambiguate when more than one *.ServiceLocator.DLL-matching assemblies are available in GAC
- Logging ServiceLocator disambiguation errors at Unexpected level to make sure they don't go unnoticed