Filter cancelling WaitTargetObject when client requests skill/spell/use

[JakubLinhart]

If a script calls WaitTargetObject, but server doesn't request a target for some reason, then WaitTargetObject sends the target to server even when user does a targeted action. Example (UOErebor)

1. Healing calls WaitTargetObject(UO.Me); and uses bandages.
2. A player doesn't have any clean bandages so server never asks for a target.
3. The player casts a spell and WaitTargetObject kicks in - targets the player.

Script must handle these cases but Injection could be a little bit more safe.

The filter prohibits conscious use of this behavior - it could be supported by a new argument of WaitTargetObject (filter on/filtr off).