Groups and Containers: Don't bubble kill, revive, exists, active, visible, and alive down to members #3612

Calling kill() or revive() on any group kills() or revives each member, but killing a group would have the same effect as killing the members since the group doesn't update or draw. This is espcially true for containers, and my most hated feature of FlxSpriteGroup/Containers is that setting exists sets exists all the way down. killing the group hides all members, but if a group had killed members when it was killed, reviving it should not revive those members.

I wanna lock this new behavior behind an optional compile flag, where a warning is given if they do set the flag or the counter-flag for their project. eventually we will warn for the counter-flag before removing the option