[talk-ch] 2017 municipality mergers

I merged Cresciano, Iragna, Lodrino and Osognato Riviera today (a bit late as the change was scheduled for the 2nd of April), which completes this years lot of mergers.

Given that we have been maintaining the boards now for a longish time in OSM, we should likely start a project to re-verify them against current official boundaries some time in the near future, at the same time we could have a look at the district boundaries which are likely not in a good state (with the exception of Graubünden).

Simon