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/bin/Res/sets/primitives/_macros.txt

@@ -218,6 +218,9 @@
 # Eternalize 
 #AUTO_DEFINE _ETERNALIZE_ name(Eternalize) clone and!( transforms((Zombie,removemc,setpower=4,settoughness=4,black)) forever )! assorcery
 
+# Explores
+#AUTO_DEFINE _EXPLORES_ name(Explores) reveal:1 optionone if type(land|reveal)~lessthan~1 then transforms((,newability[counter(1/1)])) forever optiononeend optiontwo if type(land|reveal)~morethan~0 then name(move to Hand) target(<1>*|reveal) moveto(myHand) else transforms((,newability[Choice name(back to library) target(<1>*|reveal) moveto(mylibrary)],newability[Choice name(put into Graveyard) target(<1>*|reveal) moveto(myGraveyard)])) oneshot optiontwoend afterrevealed explores afterrevealedend revealend
+
 # Discard a card. If you do, draw a card
 #AUTO_DEFINE _DISCARD&DRAW_ reject notatarget(*|myhand) and!(draw:1 controller)!