The pull request from argrath would have moved the definition of
VDECL from tradstdc.h to vmsconf.h because some out of date references
to it in sys/vms/*.c were the only place it still appeared to be used.
Instead of applying that, remove those old references.
NetHack 3.7.x requires C99 so just remove VDECL since it was present
in order to support pre-ANSI compilers. (There is at least one
comment that still mentions it though.)
This also gets rid of another chunk of tradstdc.h that was allowing
either pre-ANSI or nearly-ANSI compilers to deal with nethack's old
code. I left the USE_STDARG/USE_VARARGS/USE_OLDARGS stuff in place
even though anything supporting C99 shouldn't need that. Some or
all of the [UN]WIDENED_PROTOTYPES stuff is still there too.
Closes#1030