Convert (most) functions in src to standard C.

Convert (most) functions in src to standard C.
* src/alloc.c: Convert function definitions to standard C.
* src/atimer.c:
* src/bidi.c:
* src/bytecode.c:
* src/callint.c:
* src/callproc.c:
* src/casefiddle.c:
* src/casetab.c:
* src/category.c:
* src/ccl.c:
* src/character.c:
* src/charset.c:
* src/chartab.c:
* src/cmds.c:
* src/coding.c:
* src/composite.c:
* src/data.c:
* src/dbusbind.c:
* src/dired.c:
* src/dispnew.c:
* src/doc.c:
* src/doprnt.c:
* src/ecrt0.c:
* src/editfns.c:
* src/fileio.c:
* src/filelock.c:
* src/filemode.c:
* src/fns.c:
* src/font.c:
* src/fontset.c:
* src/frame.c:
* src/fringe.c:
* src/ftfont.c:
* src/ftxfont.c:
* src/gtkutil.c:
* src/indent.c:
* src/insdel.c:
* src/intervals.c:
* src/keymap.c:
* src/lread.c:
* src/macros.c:
* src/marker.c:
* src/md5.c:
* src/menu.c:
* src/minibuf.c:
* src/prefix-args.c:
* src/print.c:
* src/ralloc.c:
* src/regex.c:
* src/region-cache.c:
* src/scroll.c:
* src/search.c:
* src/sound.c:
* src/strftime.c:
* src/syntax.c:
* src/sysdep.c:
* src/termcap.c:
* src/terminal.c:
* src/terminfo.c:
* src/textprop.c:
* src/tparam.c:
* src/undo.c:
* src/unexelf.c:
* src/window.c:
* src/xfaces.c:
* src/xfns.c:
* src/xfont.c:
* src/xftfont.c:
* src/xgselect.c:
* src/xmenu.c:
* src/xrdb.c:
* src/xselect.c:
* src/xsettings.c:
* src/xsmfns.c:
* src/xterm.c: Likewise.