Previously, ObjJ was ignoring unknow ivar type. This patch adds some check to ensure the type is either a known class, the current class
itself, a global, a basic JS type or a declared custom type.
In order to declare custom types, this patch introduces the @typedef keyword.
For instance, this will throw a warning:
```objj
@import <Foundation/Foundation.j>
@implementation MyClass: CPObject
{
NUSuppaType mode;
}
@end
```
This will not:
```objj
@import <Foundation/Foundation.j>
@typedef NUSuppaType
@implementation NUMyClass: CPObject
{
NUSuppaType mode;
}
@end
```
Declared types are shared accross all application, one type can only be declared once.