* nix/nix-daemon/guix-daemon.cc (GUIX_OPT_TIMEOUT) (GUIX_OPT_MAX_SILENT_TIME): New macros. * nix/nix-daemon/guix-daemon.cc (options): Add '--timeout' and '--max-silent-time'. (parse_opt): Honor them. * tests/guix-daemon.sh: Add test. * doc/guix.texi (Invoking guix-daemon): Document the options. (Common Build Options): Properly describe default timeout/max-silent-time value. Add cross-ref to "Invoking guix-daemon".