Fixes to commander damage, deathtouch, MAT card variants.

March of the Machine: The Aftermath (MAT) card variants.
The previous implementation of the deathtouch ability had a bug that destroyed planeswalkers even with any amount of damage. This has been fixed.
If a player has been dealt 21 points of combat damage by a particular Commander during the game, that player loses a game. The damage rule with commanders was incorrect in counting any type of damage, not only combat damage.

Bug fixes:
Athreos, Shroud-Veiled
Endless Atlas
Natural State
Savage Gorger
Kytheon's Irregulars
Lion Sash
Pyrophobia
Minas Tirith
Sakashima of a Thousand Faces

projects/mtg/src/MTGRules.cpp

@@ -4077,8 +4077,11 @@ int MTGDeathtouchRule::receiveEvent(WEvent * event)
 
         if (card->basicAbilities[(int)Constants::DEATHTOUCH]||card->basicAbilities[(int)Constants::PERPETUALDEATHTOUCH]||card->LKIbasicAbilities[(int)Constants::DEATHTOUCH]||card->LKIbasicAbilities[(int)Constants::PERPETUALDEATHTOUCH])
         {
-            _target->destroy();
-            return 1;
+            if(_target->isCreature())
+            {
+				_target->destroy();
+				return 1;
+            }
         }
     }
     return 0;