Fixed code completion for C# 3.0 projects - reference to mscorlib was missing.

src/AddIns/BackendBindings/Boo/BooBinding/Project/Src/BooProject.cs

@@ -102,6 +102,7 @@ namespace Grunwald.BooBinding
 		public override IEnumerable<ReferenceProjectItem> ResolveAssemblyReferences(CancellationToken cancellationToken)
 		{
 			ReferenceProjectItem[] additionalReferences = {
+				new ReferenceProjectItem(this, "mscorlib"),
 				new ReferenceProjectItem(this, "System")
 			};
 			ReferenceProjectItem[] booReferences = {

src/Main/Base/Project/Src/Project/MSBuildBasedProject.cs

@@ -145,7 +145,10 @@ namespace ICSharpCode.SharpDevelop.Project
 		
 		public override IEnumerable<ReferenceProjectItem> ResolveAssemblyReferences(CancellationToken cancellationToken)
 		{
-			return MSBuildInternals.ResolveAssemblyReferences(this);
+			ReferenceProjectItem[] additionalItems = {
+				new ReferenceProjectItem(this, "mscorlib")
+			};
+			return MSBuildInternals.ResolveAssemblyReferences(this, additionalItems);
 		}
 		
 		#region CreateProjectItem