Throw error on onremove notify component being included

[Kelwan]

When an onremove notify is used for a component in a system, it shouldn't be allowed to have it included in the system itself. The interpreter should give an error to prevent inclusion.

Example:

system NotifyRemoveExample {
	readonly NotifyComponentA;
	notify {
		onremove NotifyComponentA; // Component with onremove is included in the system. Error!
	}
}