Adapt the MS-DOS build to the latest changes.

Adapt the MS-DOS build to the latest changes.

 msdos/mainmake.v2 (bootstrap-clean): Do a maintainer-clean in lib, not
 bootstrap-clean (which doesn't exist).
 msdos/inttypes.h (PRIuMAX) [__DJGPP__ < 2.04]: Define to "llu".
 msdos/sedleim.inp (MKDIR_P): Edit to DOS "md" command.
 msdos/sed1v2.inp: (LIB_CLOCK_GETTIME): Edit to empty.
 Remove lines that invoke PAXCTL.
 (clean): Fix recipe not to run Unixy shell commands.
 msdos/sed2v2.inp (GETTIMEOFDAY_TIMEZONE): Edit to 'struct timezone'.
 (HAVE_STRNCASECMP): Edit to 1.
 msdos/sed3v2.inp (LIB_CLOCK_GETTIME): Edit to empty.
 (C_SWITCH_SYSTEM): Add "-I../msdos".
 msdos/sedlibmk.inp (GNULIB_GETTIMEOFDAY, GNULIB_PSELECT)
 (GNULIB_SELECT, HAVE_STRUCT_TIMEVAL, HAVE_SYS_SELECT_H)
 (HAVE_SYS_TIME_H, NEXT_AS_FIRST_DIRECTIVE_SYS_SELECT_H)
 (NEXT_AS_FIRST_DIRECTIVE_SYS_TIME_H, NEXT_SYS_SELECT_H)
 (NEXT_SYS_TIME_H, REPLACE_GETTIMEOFDAY, REPLACE_PSELECT)
 (REPLACE_STRUCT_TIMEVAL): Edit to appropriate values.
 (BUILT_SOURCES): Edit out sys/select.h and sys/time.h.
 (mostlyclean-local, distclean-generic): Fix recipe not to run
 Unixy shell commands.

 src/sysselect.h [DOS_NT]: Don't include sys/select.h.
 src/s/ms-w32.h (select, pselect): Don't define here, they are
 defined in sysselect.h
 src/sysselect.h (pselect) [!HAVE_PSELECT]: Redirect to sys_select.
 src/sysdep.c: Don't include dos.h and dosfns.h.
 src/process.c (sys_select):
 src/msdos.c (sys_select): Accept one more argument and ignore it.
 src/msdos.c (event_timestamp, sys_select): Use gnulib's gettime;
 adapt data types and code to that.
 src/dosfns.c:
 src/msdos.c (gettime, settime): Define away the prototypes in dos.h,
 which clashes with the gnulib function of the same name.

 lisp/emacs-lisp/timer.el (timer-until): Subtract results of
 float-time, instead of taking float-time of the result of
 time-subtract, since float-time signals an error for negative time
 arguments.