Feature request: allow enemies to use Praise Self with filters

[WoolieWool]

It would be really cool to allow enemies to transmit Praise Self messages using IFF filters, essentially taunting the player after killing one of their allies, like this:

$Message:                       XSTR("A proper fate for a coward!", -1)
        +Persona:                   Wingman V1
        +Avi Name:                  Head-VP2
        +Wave Name:                 V1_praiseself_hostile.wav
    $Filter by sender:
        +Team:                      Neutral
        +Team:                      Hostile