For now, ground snd_restart and snd_unloadallsounds if the client is still connected...

For now, ground snd_restart and snd_unloadallsounds if the client is still connected, because DP keeps references to the sfx_t * that are being freed in the precache list. A real fix however would be ditching snd_unloadallsounds completely, and making a snd_reload command that unloads the sounds that are not being used at the moment, and reloads the sounds that are referenced.

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@7563 d7cf8633-e32d-0410-b094-e92efae38249