deal with some warnings and misc fixes

- add acknowledgements to README
- nuke unused variables that won't ever be used
- remove FIXME and STUB
- have screenseg as an actual pointer, altough still invalid
- ca: uninitialized pointer
- draw: partial ScaleOneWall asm, waiting on compiled scalers stuff
- game: p9 timing stuff for PROFILE
- in: IN_GetJoyAbs asm
- misc: partial fix for rcr() and rcl() bullshit, itoa instead of ltoa, and fix
  inportb taking u8 for port
- sd: benign bug in SD_Default
- us1: refactor parts
- us2: remove key macros for UserItem{,Group} and init explicitely every struct
  member, showing how useless some of them are
- vw: another bitbug when screwing around with outb(); fix incorrect assumption
  of movsb in place of stosb in VW_Bar (d'oh!); VW_CGAFullUpdate asm

there actually is some code for strafing... huh.