add "teams" to organisation. Add ability to asign issues to "teams"

An organisation should have ablity to make "teams" with teamleader and other users. As follow up -you should add possibility to asaign a whole "organisation" or "team" for fxing issue - then its project leader should asign it to a specific user in his team. It would be very useful when working with external contractors (when you don't know for sure which user is responsible for what).