Yet more CNW fixes... this appears to be good all the way to Greentree now.

- saybar needs to leave cursor at 78,20 for BETTER.REF and
  TALQUIZ.REF
- buymanager and sellmanager start on the current line, not a
  hard-coded one
- buymanager and sellmanager need to clean their area on return
- handle do handlers in if before checking for begin (assuming do).
  Fixes issue in GIVE.REF where "then goto begin" was interpreted
  as "then do begin".
- "Fix" more prompt in @key to not center and always display
  "  <MORE>" as the prompt.  A number of things use @key after @saybar