added stack check, modified life check

if activating ability, playing a land or casting sorcery spell at
sorcery level(timing restriction), if the stack is not empty, don't
allow it. Modified the life state check, if any of the players would
lose the game, allow the gamestateeffects to check... added
reduceto:value for ali from cairo...

projects/mtg/src/MTGCardInstance.cpp

@@ -739,6 +739,20 @@ int MTGCardInstance::getCurrentToughness()
     return toughness;
 }
 
+//check stack
+bool MTGCardInstance::StackIsEmptyandSorcerySpeed()
+{
+    if((getObserver()->mLayers->stackLayer()->count(0, NOT_RESOLVED) == 0) &&
+        (getObserver()->getCurrentGamePhase() == MTG_PHASE_FIRSTMAIN ||
+        getObserver()->getCurrentGamePhase() == MTG_PHASE_SECONDMAIN) &&
+        controller() == getObserver()->currentPlayer &&
+        !getObserver()->isInterrupting)
+    {
+		return true;
+    }
+    return false;
+}
+
 int MTGCardInstance::canBlock()
 {
     if (tapped)