* initial checkin of the LinuxTag vCC database importer
  - working: person, event, paper
  - known issues: roles, paper status, languages
* fixed a bug in frab data model with regards to availabilites
* fixed a bug related to availability at conferences
Revert "* initial checkin of the LinuxTag vCC database importer"

This reverts commit ff4564f8185973fda28347a8b016ac8533b524e8.
Revert "* fixed a bug related to availability at conferences"

This reverts commit 3b6f8ccc6de8ce6a42ac7d65cfdae57a55bbd7a8.
* initial checkin of the LinuxTag vCC database importer
  - working: person, event, paper
  - known issues: roles, paper status, languages
* fixed a bug in frab data model with regards to availabilites