Fixed|Hexen: Special palettes of Mage/Cleric weapons

The special palettes of the Mage/Cleric weapon 4 were being
overwritten by the pain/poison/etc. filter color.

Also addressed some SFX played by the Hexen weapon psprites: if
played locally by the client, the server shouldn't send another sound
playback request about the same animation.

Todo: While missiles are spawned on the server, the client may handle
any audio/visual psprite feedback on its own for a better, lag-free
experience.