Makes companions (and pseudo-companions like Sydney) essential through a global script, provided that they are following the player and not engaged in...
Flags 'essential' the player's companions, plus Red, Shorty, Sticky and Sydney, so that they will not die.
In contrast to version 1.0, this is not done through dialogue, but through a global script, that will switch the follower back to non-essential if they are currently engaged in combat with the player.
Because the script only executes every five seconds, it is possible that the companion may not die immediately if the player decides to kill them, instead falling unconscious. If that happens, just wait for them to get back up, choose a slow-to-kill weapon like a baseball bat or pistol and attack slowly until they turn hostile - they should then die provided you are in combat for more than five seconds.
If the player is not attacking the companion, they should remain 'essential' so long as their status is set to 'hired'. The exceptions are Red, Shorty, Sticky and Sydney, who will remain 'essential' all the time they are not in combat with the player.