9.4 changes:
- updated version to 9.4
    bintar README NOTICE makefiles/Mf-install.in scheme.1.in
    c/Makefile.i3nt c/Makefile.a6nt c/Makefile.ti3nt c/Makefile.ta6nt
    mats/bldnt.bat workarea c/scheme.rc s/7.ss s/cmacros.ss
    release_notes/release_notes.stex csug/csug.stex
- added missing include
    killme.c
- added new mat verifying that primitives raise exceptions for invalid
  arguments based on primdata.ss signatures.  fixed some of those
  signatures, which weren't otherwise used except for arity checking.
  fixed some issues turned up by the test with who reports errors
  and how.
    primdata.ss, 5_1.ss, 7.ss, compile.ss, cpnanopass.ss, fasl.ss,
    interpret.ss, io.ss, record.ss, syntax.ss,
    primvars.ms, 5_1.ms, 7.ms, 8.ms, record.ms, mats/Mf-base,
    root-experr*, patch*
- string comparisons (string=?, string-ci<?, etc.) now get out fast
  when handed eq arguments.
    5_4.ss
- changed representation of most-negative iptr, I32, and I64 to make
  Visual C compiler happy.  updated windows make files, which had
  fallen out of date.  added missing hsrc= files sort.h and thread.h
  so they show up in the Windows workarea c directory.
    cmacros.ss,
    fasl.c, number.c, c/Mf-base, c/Makefile.{t,}{i3,a6}nt