lib/Odin.pm, bin/pastebin.userv: Use our own simple option parser.

lib/Odin.pm, bin/pastebin.userv: Use our own simple option parser.

Perl's Getopt::Std doesn't let us handle options which are repeated.
Getopt::Long can do this, but it involves a lot of messing about to set
it up, and it has slightly bizarre option-cuddling behaviour.  So we
implement a very simple option parser and use it instead.