added ccAddr for TubMailSender.sendMail; new IMAP methods

• TubMailSender.sendMail now accept optional ccAddr property - the CC address in email
• UBMail.UBMailImap: new methods:
  • setFlags set a flag or set of space-separated flags for a message
  • addFlags add a flag or set of space-separated flags for a message
  • delFlags remove a flag or set of space-separated flags for a message
  • copy copy a message to a destination folder
  • move move a message to a destination folder The new methods are useful for different mail processing scenarios:
  • Mark processed messages with a flag (keyword)
  • Move processed messages to another folder