Merge branch 'T23268-clang-compilation-fixes'

Summary:
Merge branch 'T23268-clang-compilation-fixes'

Removed deprecated throw specifications

Fixed indent semantic

Fixed some switch fall-throughs and strange if conditions

Not tested, mostly kept the original behaviour or used common sense

Fixed moc warning

Fix Vigra compilation error on GCC 7

Test Plan: compiles successfully, possible behaviour changes have been marked with TODO, usually the code seemed to be broken anyway

Reviewers: goch, kislinsk

Maniphest Tasks: T23268

Differential Revision: https://phabricator.mitk.org/D63