Rename integerp->fixnum, etc, in preparation for bignums

Rename integerp->fixnum, etc, in preparation for bignums

* src/json.c, src/keyboard.c, src/keyboard.h, src/keymap.c,
src/kqueue.c, src/lcms.c, src/lisp.h, src/lread.c, src/macros.c,
src/marker.c, src/menu.c, src/minibuf.c, src/msdos.c, src/print.c,
src/process.c, src/profiler.c, src/search.c, src/sound.c,
src/syntax.c, src/sysdep.c, src/term.c, src/terminal.c,
src/textprop.c, src/undo.c, src/w16select.c, src/w32.c,
src/w32console.c, src/w32cygwinx.c, src/w32fns.c, src/w32font.c,
src/w32inevt.c, src/w32proc.c, src/w32select.c, src/w32term.c,
src/w32uniscribe.c, src/widget.c, src/window.c, src/xdisp.c,
src/xfaces.c, src/xfns.c, src/xfont.c, src/xftfont.c, src/xmenu.c,
src/xrdb.c, src/xselect.c, src/xterm.c, src/xwidget.c: Rename
INTEGERP->FIXNUM, make_number->make_fixnum, CHECK_NUMBER->CHECK_FIXNUM,
make_natnum->make_fixed_natum, NUMBERP->FIXED_OR_FLOATP,
NATNUMP->FIXNATP, CHECK_NATNUM->CHECK_FIXNAT.