(longopts) [! NO_SOCKETS_IN_FILE_SYSTEM]: Don't show option --socket-name.

(longopts) [! NO_SOCKETS_IN_FILE_SYSTEM]: Don't show option --socket-name.
(decode_options): Don't get EMACS_SERVER_FILE here, it could override command
line options.
(decode_options) [! NO_SOCKETS_IN_FILE_SYSTEM]: Don't parse "-s" option.
(fail): Don't check for missing arguments, it is now done in set_socket.
(file_name_absolute_p): New function (loosely based on the one in fileio.c).
(initialize_sockets): Don't check for duplicate loading of Winsock.
(get_server_config): Only try relative paths in the default directory locations.
(set_tcp_socket): Don't call INITIALIZE().  Warn when connecting to a remote
server.
(set_socket): Call INITIALIZE().  Search explicit command-line arguments, then
environment variable EMACS_SERVER_FILE, then implicit socket paths, before
trying the alternate editor.
(main): Use file_name_absolute_p.