Added in check for undefined type. This allows you to define optional…

…, transient objects per the 'An Object Attribute' section of http://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/CoreData/Articles/cdNSAttributes.html%23//apple_ref/doc/uid/TP40001919-SW1

templates/machine.h.motemplate

@@ -62,12 +62,14 @@
 
 @interface _<$managedObjectClassName$> (CoreDataGeneratedPrimitiveAccessors)
 <$foreach Attribute noninheritedAttributes do$>
+<$if Attribute.hasDefinedAttributeType$>
 - (<$Attribute.objectAttributeType$>*)primitive<$Attribute.name.initialCapitalString$>;
 - (void)setPrimitive<$Attribute.name.initialCapitalString$>:(<$Attribute.objectAttributeType$>*)value;
 <$if Attribute.hasScalarAttributeType$>
 - (<$Attribute.scalarAttributeType$>)primitive<$Attribute.name.initialCapitalString$>Value;
 - (void)setPrimitive<$Attribute.name.initialCapitalString$>Value:(<$Attribute.scalarAttributeType$>)value_;
 <$endif$>
+<$endif$>
 <$endforeach do$>
 <$foreach Relationship noninheritedRelationships do$>
 <$if Relationship.isToMany$>