Display information about unsubscribed members (if they had submitted addon-information and/or payment)
Test for activity.memberIdsOfAddons()
grouped general addon tests into their own describe.
Extracting the addon lines for unsubscribed members that have addon or payment info and displaying them on the management page.
Merge pull request #742 from NicoleRauch/master

Display unsubscribed participants that have addon or payment information.
Removed setup duplication in the tests (thanks to Teamscale).
unsubscribed member does not necessarily exist any more...
Merge pull request #743 from NicoleRauch/master

Small fixes and improvements
call "simon" via "sandbox" now