Log Message:
Update mksh to R40f.

mksh R40f fixes a critical bug as well as this:
 [tg, RT] Implement fcntl(2)-based advisory locking as an alternative
  iff flock(2) is not found (LP: #912691); keep trying in the face of EINTR
 [tg] Fix severe regression wrt. initialising tty(4) states
 [tg] Improve testsuite, build-time checks and debugging output
 [tg, RT, winstonw] Improve portability to BeOS (works), Cygwin (good),
  Dell UNIX (works somewhat, but not with gcc), LynxOS (works somewhat),
  NeXTstep (works but not OpenStep 4.2), USL C compiler, SCO OpenServer (good),
  SCO UnixWare (good), Plan 9 (still broken), Syllable Desktop (broken?)
 [tg] rlim_t is supposed to be unsigned
 [tg] Some code, warning and spelling cleanup
 [tg] New Build.sh environment configurable: AWK (= awk)
 [tg, DONG-DONG YANG] Add safety net in the Emacs line editing code
 [tg] No longer rely on env(1), id(1), printf(1) in the testsuite, and
  strcasecmp(3), strcasestr(3), strncasecmp(3) in the code
 [tg, stsc, RT] Reduce system requirements of check.pl further

mksh R40e is another must-have bugfix update:
 [tg, Jilles Tjoelker] skip readonly check in unevaluated ternary twig
 [tg, anonymous] fix all remaining ifs.sh testcases
 [tg] No longer try to build with GCC and C99 extensions
 [tg, Jilles Tjoelker] Do not expand aliases in COMSUB twice
 [tg] Honour UTF-8 multi-byte character boundaries when doing partial
  tab-completion insertions (LP: #909025) to fix RedHat BZ#745702
 [tg] Fix R40 (BZ#496791) regression with IOACT in TIF (LP: #907224)
 [tg, ft] Darn persistent history code worst offenders (LP: #906914)
 [tg] Fix some gc-sections, GCC and Clang/scan-build warnings/issues
 [tg, 28C3] dot.mkshrc hash functions: partially address LP: #909818
 [tg] Only compile divmod(0x80000000, -1) code in when not unneeded
 [tg, RT] Move mirtoconf checks and INCLUDES_ONLY parts of
  sh.h around to ensure prerequisites are always available
 [tg, RT, ir0nh34d] Pass mksh.exe to testsuite, if such thing is generated,
  and deal with Cygwin passing just "mksh" in argv[0] in such cases
 [tg] Imply -DMKSH_ASSUME_UTF8=0 on MSYS; optimise checks
 [tg, Jb_boin] Fix regression introduced in R35b by jaredy's security
  patch where TTIME trashed a non-TCOM string argument (e.g. in TFOR)
 [tg] Better support for tcc; fix GCCism that accidentally crept in
 [tg] Deal with UTF-8 when reporting jobs' commands
 [RT] Add SkyOS to known OS list
 [tg, RT] Support Minix in its variants Minix 3 and Ninix 3 better
 [tg] Drop some Android-specific unused code (lsmod builtin)
 [tg, RT, lewellyn] Support QNX and various versions of BSD/OS better
 [tg] More code cleanup and new developer-only debugging functions
 [tg, Andrew Kudryashov] Fix some tab completion related escaping bugs
 [tg, draenog] Honour COLUMNS and LINES from the environment in scripts
 [tg, winstonw] The sleep built-in utility now blocks more signals
 [tg] Warn when using another deprecated function that will be removed