[S12] Expanded inscrutable acronym for VienosNotes++

The spec is inscrutable enough as it is without people wasting 20 minutes
to find the meaning of infrequent acronyms.

See http://twitter.com/VienosNotes/status/16767710964752384

Author: Carl Masak

S12-objects.pod

@@ -13,8 +13,8 @@ Synopsis 12: Objects
 
     Created: 27 Oct 2004
 
-    Last Modified: 5 Nov 2010
-    Version: 111
+    Last Modified: 20 Dec 2010
+    Version: 112
 
 =head1 Overview
 
@@ -129,7 +129,7 @@ An "isa" is just a trait that happens to be another class:
 
     class Dog is Mammal {...}
 
-MI is specified with multiple C<is> modifiers:
+Multiple inheritance is specified with multiple C<is> modifiers:
 
     class Dog is Mammal is Pet {...}