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  fallen out of date.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
- The scheme.h definition of Sfixnum(x) now uses multiply rather than
  left shift to avoid counting on the behavior of << on negative numbers,
  which is undefined in C.
    mkheader.ss
- Fixed a couple of casts, one harmless and the other causing
  Sinteger64_value to return 0 for the most-negative I64 on 32-bit
  builds.
    number.c
- The configure-generated Makefile distclean target no longer removes
  zlib and nanopass, since they are logically part of the git clone.
  It does run make distclean in zlib.
    makefiles/Makefile.in
- converted s_test_schlib shifts of -1 to equivalent shifts of 1 to
  avoid undefined left-shift behavior on negative numbers.
    prim5.c
- added if(---) {} wrapper around call to WRITE in display macro to
  silence unused return-value warnings.
    prim5.c
- liberalized get-mode check for ../mats.  it's not our business whether
  people make their directories group and/or other writeable.
    6.ms
- make test now prints the actual relative path to summary in the
  "check summary" message, whether invoked from the top-level directory
  or from the workarea.
    Makefile.in, Makefile-workarea.in
- configure now just uses cat to copy Makefile-workarea.in to $w/workarea,
  since the file is presently the same regardless of the configuration.
    configure
- fixed time-utc->date test in mat time&date-printing to work regardless of
  what locale (and time zone) the host machine has set.
    date.ms
- fixed date->time-utc to honor the zone-offset field when converting a date
  object to a time-utc object.
    stats.c,
    date.ms
- fixed incorrect handling of library-extension when searching wpo files
    compile.ss,
    7.ms
- modified floatify_normalize to properly round denormalized results.
  obviated scale_float in the process.
    number.c,
    ieee.ms
- fixed 0eNNNN for large NNNN to produce 0.0 rather than infinity
    strnum.ss,
    5_3.ms
- the reader now raises an exception with condition type implementation
  restriction (among the other usual lexical condition types), and
  string->number now raises #f, for #e<m>@<a>, where <m> and <a> are
  nonzero integers, since Chez Scheme can't represent polar numbers other
  than 0@<n> and <n>@0 exactly.  <m>@<a> still produces an inexact result,
  i.e., we're still extending the set of inexact numeric constants beyond
  what R6RS dictates.  doing this required a rework of $str->num, which
  turned into a fairly extensive rewrite that fixed up a few other minor
  issues (like r6rs:string->number improperly allowing 1/2e10) and
  eliminated the need for consumers to call $str->num twice in cases
  where it can actually produce a number.  added some related new tests,
  including several found missing by profiling.  added a couple of
  checks to number->string the absence of which was causing argument
  errors to be reported by other routines.
    strnum.ss, exceptions.ss, read.ss
    5_3.ms, 6.ms, root-experr*, patch*
- added pdtml flag, which if set to t causes profile-dump-html to be
  called at the end of a mat run.
    mats/Mf-base