Download and Magic Guard fixes

Gen 4 Download resolves at like 6 different points, but the only useful ones are UponSetup, EndTurn, and BeforeTargetList. 

The rest are impossible to recreate (or redundant) in a Gen 4 setting:
-There's no possible way to have the ability not activate before your attack, but then activate after your attack, on the same turn. 
-The "opponent switching in" is irrelevant because the only thing it would affect is Imposter, a Gen 5 ability. 
-Then there's no way to have it not resolve as the turn starts, but then resolve when the Pokemon actually goes to attack, on the same turn.