CPAN::Shell 's' command

I'm playing with a new command for the CPAN::Shell: 's' for search on http://search.cpan.org.

It takes a single argument (can be a module, distribution, bundle or author name), checks the CPAN indexes to see which type it is, creates the proper URL for it at search.cpan.org and opens your browser with it.

The last bit, opening a browser with it, is very very immature. Right now it only works on Mac OS X. I'm hopping to get the experience to do it right from the Browser::Open distribution.

If no object is found, sends the user to the generic search interface.

The current hackish implementation can be found on my s_command topic branch (its a topic branch, I will rebase it on occasion onto master).