Add --version (or -v) command line switch

[tredondo]

If proxychains is installed from a package repo, or comes with a distro, the user can't easily tell what version they're on.

 proxychains4 --help

Usage:  proxychains4 -q -f config_file program_name [arguments]
        -q makes proxychains quiet - this overrides the config setting
        -f allows one to manually specify a configfile to use
        for example : proxychains telnet somehost.com
More help in README file