Avoid "catch-all" exception handlers

[Reimar Bauer]

We have on various modules just

except:

That may catch all kind of errors and may be hide some we could solve.

[Reimar Bauer]

replaced a wildcard exception by the proper type.

See issue #42

→ <<cset 44d40aa71483>>

[Reimar Bauer]

TODOs and logging for catch-all exceptions added, addresses #42

→ <<cset 9bc319ae4d2b>>

[Joern Ungermann]

Doing this has made the MSS more unreliable as unforeseen errors astonishingly often result in an avoidable application crash combined with loss of data. We should either a) distinguish between a hardened and developer mode b) re-add wildcard exceptions with unmissable, report this bug pop-up windows on occurance. There are many places where no action would be fine whereas an application crash is always a no-go.

[Reimar Bauer]

allmost all wildcard exceptions replaced.