BSD-able Makefile, add a man page (that also puts a bold warning about
the weakness of the encryption), and implement the -k option for
compatibility with other vendor's implementations. (Unlike those
other vendors, we actually also document this option and its
problems.)
There are more violations of style(9) in it, like the not-use of
getopt(3), but it's not worth the while fixing all of this.
Cryptbreakers Workbench. While arguably a rather weak encryption,
it's in some use in the Internet still, and provided by a bunch of
other Unix systesms, so we include it here for compatibility.
Silently agreed by: core
