Add System.Core references to OpenSim.Region.CoreModules.* to fix windows build
Add System.Core references to OpenSim.Region.CoreModules.* to fix windows build

This addresses http://opensimulator.org/mantis/view.php?id=4923

TechplexEngineer/Aurora-Sim,TechplexEngineer/Aurora-Sim,TechplexEngineer/Aurora-Sim,TechplexEngineer/Aurora-Sim