#1315 dont use the type systems resource to add built in properties

Cause the Typesystem resource may be loaded via Editing domain and this
would require a valid write transaction

plugins/org.yakindu.sct.generator.genmodel/src/org/yakindu/sct/generator/genmodel/typesystem/BuiltinDeclarations.xtend

@@ -11,11 +11,13 @@
 package org.yakindu.sct.generator.genmodel.typesystem
 
 import com.google.inject.Inject
+import com.google.inject.Singleton
+import org.eclipse.emf.ecore.resource.Resource
+import org.eclipse.emf.ecore.xmi.impl.XMIResourceImpl
 import org.eclipse.xtend.lib.annotations.Accessors
 import org.yakindu.base.types.Property
 import org.yakindu.base.types.Type
 import org.yakindu.base.types.TypesFactory
-import org.yakindu.base.types.typesystem.AbstractTypeSystem
 import org.yakindu.base.types.typesystem.ITypeSystem
 import org.yakindu.sct.model.sgen.util.BuiltinDeclarationNames
 
@@ -24,6 +26,7 @@ import org.yakindu.sct.model.sgen.util.BuiltinDeclarationNames
  * 
  */
 @Accessors(PUBLIC_GETTER)
+@Singleton
 class BuiltinDeclarations implements BuiltinDeclarationNames {
 	protected TypesFactory typesFactory
 	protected ITypeSystem typeSystem
@@ -33,23 +36,24 @@ class BuiltinDeclarations implements BuiltinDeclarationNames {
 	protected Property hostname
 	protected Property username
 
+	protected Resource builtinResource
+
 	@Inject
 	new(ITypeSystem typeSystem) {
 		this.typesFactory = TypesFactory.eINSTANCE
 		this.typeSystem = typeSystem
-		
+		builtinResource = new XMIResourceImpl
 		val stringtype = typeSystem.getType(ITypeSystem.STRING)
-		
 		sct_version = createProperty(SCT_VERSION_VAR, stringtype)
 		timestamp = createProperty(TIMESTAMP_VAR, stringtype)
 		hostname = createProperty(HOSTNAME_VAR, stringtype)
 		username = createProperty(USER_VAR, stringtype)
 	}
-	
+
 	def protected Property createProperty(String name, Type type) {
-		typesFactory.createProperty => [prop |
-			(typeSystem as AbstractTypeSystem).resource.contents += prop
-			
+		typesFactory.createProperty => [ prop |
+			builtinResource.contents += prop
+
 			prop.name = name
 			prop.typeSpecifier = typesFactory.createTypeSpecifier => [
 				it.type = type