Merge remote-tracking branch 'origin/T19830-fix-rendering-of-arbitrary-TimeGeometries-master' into master

Summary:
fixed Ralf's review remarks (see D3).

Signed-off-by: Ralf Floca <r.floca@dkfz-heidelberg.de>

fixed gcc issues.

Signed-off-by: Ralf Floca <r.floca@dkfz-heidelberg.de>

Reverting commit for changes to the time bound determination strategy. See also the comment in phabricator issue T19830.

Signed-off-by: Ralf Floca <r.floca@dkfz-heidelberg.de>

Test Plan: code review and unit tests

Reviewers: O1 MITK Core, goch

Reviewed By: O1 MITK Core, goch

Subscribers: goch

Maniphest Tasks: T19830

Differential Revision: https://phabricator.mitk.org/D43