Re-implemented post damage invuln as a coroutine, purged IActorVisualBehavior from the system (we should just use MonoBehaviors instead).
Trying to reduce timing issues in possession/depossession coroutines - the answer is to put more IN the coroutines themselves, which kinda sucks.
The annoying heroling "tugboat push" bug is fixed - a relic from old logic that tried to prevent herolings from being reabsorbed.
Better shield color
- avoid "ghost" shields by clamping them to a minimum alpha
- fixed the insta-recharge shields for the player
- moved enemy shields from MOB_AMMO to MOB collision layer (this is consistent with friendly shields being on the FRIENDLY layer) so that herolings now collide with them
- added Actor.isCapturable so that herolings do not capture things like FRY and SHIELD
- fixed bounce velocity and heading of weapons
- spruced up shield poly collider
- fixed rocket trail layout
- made launched shields less heavy