added countertrack(counterstring) MTGAbility

what this does currently is remove a counter of the type counterstring and when the ability is destroyed it puts the counter back for us.
meant for weapons used as follows.
auto=teach(creature) countertrack(0/0,1,hand)

when the creature is equipped with this weapon it will remove a hand counter from the creature, when you remove the weapon, or the weapon is destroyed or whatever...it will put a hand counter back on the creature.

added dualwielding thisdescriptor...
auto=this(dualwielding) 2/2
auto=this(dualwielding) firststrike

enabled "restriction{" on phasebased triggers @next and @each...

i will work more on countertrack to extend it to domains if it currently isnt possible to use it in this case(haven't tested it on domains)....

projects/mtg/src/MTGCardInstance.cpp

@@ -138,6 +138,7 @@ void MTGCardInstance::initMTGCI()
     damageToOpponent = false;
     damageToController = false;
     wasDealtDamage = false;
+    isDualWielding = false;
     suspended = false;
     castMethod = Constants::NOT_CAST;
     mPropertiesChangedSinceLastUpdate = false;