Make (console) reports less verbose

[ascheman]

As a user of HSC I would like to get only warnings or errors on the console to make the output less verbose.
Usually, I am not interested to get a lengthy list of investigated files as long as everything is OK.
I would rather like to focus on the problems, if there are any.

However, there should be a compatibility feature flag which makes the report comparable to the 1.x reports.