screw the code sideways some more

- rewrite c3_act1.c, c3_wiz.c, c3_state.c
- c3_main: SaveTheGame, LoadTheGame, ResetGame
- c3_play: InitObjList, GetNewObj, RemoveObj
- id_ca: CAL_CarmackExpand, CA_FarRead, CA_ReadFile (eread), CA_SegWrite
  CA_LoadFile (ewrite), CA_RLEWcompress, CA_RLEWexpand, CAL_SetupMapFile,
  CA_CacheAudioChunk, CA_LoadAllSounds, CAL_ShiftSprite, CAL_CacheSprite,
  CAL_ExpandGrChunk, CA_CacheGrChunk, CA_CacheMap, CA_FreeGraphics,
  CA_SetAllPurge
- id_sd: SD_PlaySound
- id_vw: stub EGA macros, VW_Hlin, VW_Bar; VW_FreeCursor
- remove more stuff from id_us.c
- added a horrible implementation of ltoa; its use must be killed in time
- purged some unused functions

asm unported. everything is completely untested, probably doesn't work, has
probably introduced new bugs, probably is a bomb waiting to go off. my
methodoly for this has been really poor, let's hope we can clean up.