fix for cumulative upcost, extra cost were not being multiplied

[card]
name=Phyrexian Soulgorger
auto=cumulativeupcost[{S(creature|myBattlefield)}] sacrifice
text=Cumulative upkeep - Sacrifice a creature. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
mana={3}
type=Snow Artifact Creature
subtype=Construct
power=8
toughness=8
[/card]
was only charging you 1 sacrifice per upkeep.

added thisTargetComparison, this(cantargetcard(targetchooser))...its a thisdescriptor that compares if the card can be targeted by a target chooser...

projects/mtg/src/ManaCost.cpp

@@ -600,6 +600,15 @@ int ManaCost::addExtraCost(ExtraCost * _cost)
     return 1;
 }
 
+int ManaCost::addExtraCosts(ExtraCosts *_ecost)
+{
+    if (!extraCosts)
+        extraCosts = NEW ExtraCosts();
+    for(size_t i = 0; i < _ecost->costs.size(); i++)
+        extraCosts->costs.push_back(_ecost->costs[i]->clone());
+    return 1;
+}
+
 int ManaCost::isExtraPaymentSet()
 {
     if (!extraCosts)