__seguse.txt added to show _seg usage also OpenVGMFile needs to be ported to 16_snd...

__seguse.txt added to show _seg usage also OpenVGMFile needs to be ported to 16_snd.c so we can use CA MM and PM ][ ca needs huge amounts of work and i should remember what needs to be done soon also i should reverify 16_in.c to make sure it can work with other code of id engine] did some cleanings ans such also there is a glitch i see wwww