a.) Don't include a zillion system headers from "extern.h" (actually, don't
include any).
b.) Break a global jmp_buf variable into a new file, so <setjmp.h> doesn't
have to be pulled in everywhere (it's only used in two places).
The (one line) new file is (c) TNF with a three-clause license, FW(L)IW.
This merges in all such remaining changes from the Linux port of the
NetBSD games, except in hunt (where substantial changes from OpenBSD
need to be looked at).
Some such changes were previously covered in PRs bin/6041, bin/6146,
bin/6148, bin/6150, bin/6151, bin/6580, bin/6660, bin/7993, bin/7994,
bin/8039, bin/8057 and bin/8093.
integer arguments and with string arguments (cast to long, and in one
place to int). The patch here cleans this up, making it into two
separate functions; this allows for the game to be made const-correct
in future and improves portability.
The patch also contains two other fragments: a change to use the
symbolic constant SEEK_END with fseek(), and a change to use snprintf
in one place to avoid a buffer overrun.
Via PR 6569 by Joseph Myers <jsm28@cam.ac.uk>.
