- Added a RETI instruction for returning 15-bit signed immediate values.

- Changed Actor's Damage property into an actual function. All access to the damage property
  must now be done through GetMissileDamage. actor->GetMissileDamage(0, 1) is equivalent
  to the former actor->Damage, for the case where actor->Damage was not an expression. (I
  suppose I will probably need to make a thunk for DECORATE expressions that want to read it.)
- Cleaned up some decorate expression evaluation functions that are no longer used.

SVN r3919 (scripting)

src/thingdef/thingdef_properties.cpp

@@ -449,7 +449,7 @@ DEFINE_PROPERTY(painthreshold, I, Actor)
 //==========================================================================
 DEFINE_PROPERTY(damage, X, Actor)
 {
-	PROP_INT_PARM(id, 0);
+	PROP_EXP_PARM(id, 0);
 
 	// Damage can either be a single number, in which case it is subject
 	// to the original damage calculation rules. Or, it can be an expression
@@ -457,7 +457,9 @@ DEFINE_PROPERTY(damage, X, Actor)
 	// compatibility reasons, expressions must be enclosed within
 	// parentheses.
 
-	defaults->Damage = id;
+	// Store this expression here for now. It will be converted to a function
+	// later once all actors have been processed.
+	defaults->Damage = (VMFunction *)id;
 }
 
 //==========================================================================