Merge pull request #508 from NicoleRauch/master

Now a resource can have a participant limit of 0 -> nobody can register.
Changed the displayed text for zero-limit resources to not show „Full“
Introducing special GDCR Page!
microfeature: add url to ical events
helping slow travis to not fail because of timeouts
fixing build breaking mongo-db-native
Merge pull request #511 from leider/hotfix

fixing build breaking mongo-db-native
Merge commit '2de2e169e998d6b1c976d9a6826b2456d85c2bc1' into parallel

# Via Andreas Leidig (1) and leider (1)
* commit '2de2e169e998d6b1c976d9a6826b2456d85c2bc1':
  fixing build breaking mongo-db-native
Merge commit '2de2e169e998d6b1c976d9a6826b2456d85c2bc1'

# Via Andreas Leidig (1) and leider (1)
* commit '2de2e169e998d6b1c976d9a6826b2456d85c2bc1':
  fixing build breaking mongo-db-native
Revert "helping slow travis to not fail because of timeouts"

This reverts commit 191511a5d8bffea7dec94f137e9cd4664cc60b20.
Merge pull request #509 from leider/master

Introducing special GDCR Page!
Merge pull request #510 from leider/parallel

microfeature: add url to ical events