x) Catch more generic IO issues

x) Add a default filename of <unknown> for default created resources

cfg/Config.cs

@@ -91,7 +91,7 @@ namespace lib
 
 				cfg.SetFilename( filename );
 			}
-			catch( FileNotFoundException )
+			catch( IOException )
 			{
 				Type[] types = new Type[0];
 				object[] parms = new object[0];

res/Resource.cs

@@ -57,6 +57,8 @@ namespace res
 
 		//For serialization
 		public Ref()
+			:
+			base( "<unknown>" )
 		{
 		}