MIRA: add occurences editor to requirement sources
1. Open the editor of a glossary term
2. change to the tab “Glossary occurences”
—>This dialog should be renamed to “Occurences”
—>Section “Glossary entry Overview” should be renamed to
“Overview”
—>The dialog should be available also for Requirement sources
(Please do not duplicate it but if necessary extract it to independent
classes)
(Use ContextElementEditorBase)
3. Add help for occurences editor (for Glossary and Requirement sources)
(from redmine: issue id 2153, created on 2014-11-07, closed on 2015-03-23)