[licence] updated copyright years and added missing headers
[cleanup] split 'lib/cyborghood/base.rb' and reorganized requires a bit
[debug] simplify debug with debug flags, added one to allow not removing mails in the mailbox (to replay them later)
[cleanup] better class/modules names for a few items
[evol] add missing licensing terms
[evol] check new mails at a selectable minimum interval, and handle stop requests gracefully
[evol] improved IMAP message handling, and properly delete ignored or processed messages
[evol] move IMAP code into a new class