Add lib/rex/proto/pjl.rb
Add lib/rex/proto/pjl/constants.rb
Add lib/rex/proto/pjl/client.rb
Add aux/scanner/printer/printer_version
Add aux/scanner/printer/printer_ready_message
Add MC and YGN to printer_{version,ready_message}

Since you two wrote your own modules that didn't make it into Framework,
I want to show my appreciation for your giving PJL the love it deserves.

Thanks! :)
Add simplistic YARD documentation