Now we get a proper JavaScript object with a member and an addon that is used to display the payments.
Activity can now collect the registration dates of a given participant.
Add registration dates to the activity's management table.
Better error handling and some tests.
Merge pull request #665 from NicoleRauch/master

Registration dates are now shown in the activity's management table for payments.
mini "hot fix" javascript for table had 1 column too few