Worked on #54. Should be more almost ready.

With new install everything should be name correctly. For already
existing installations there are some places that need manual changes:
title for ed_cluster node should be changed to Group, all reference
fields should have title changed from Cluster to Group. Translation file
has to be reimported in order to bring in the new translations. Please
note that translation file has new translation strings and has to be
finished before the update occures.
Fixes #89. Added a check.

Added a check to only run the cycles and logic if there are some
competences chosen.