Feature Request: Fully automate viewcache clearing + database migration handling

[berrnd]

After each and every release there tend to be more and more invalid Bug reports caused by a not emptied data/viewcache directory and/or not executed database migrations, so by people who can't read README for whatever reason: How to update

I still blame everyone opening a request which could simply be solved by reading README or doing a quick and easy search beforehand, but let's finally automate that, at least to reduce the support amount for myself.

What's stored in data/viewcache is (currently) dependent on / specific to the version and the config options BASE_PATH and BASE_URL. So let's somehow auto-clear that directory when any of this changes (normally that means an update happened).

And since new database migrations can only come with a new release, let's then take this also to fire off them.