OO-642: fix behavior of minimized contact window of chat
OMA-22: enhance calendar REST API
OMA-22: enhance calendar REST API
OMA-22: enhance calendar REST API
non-jira: typo
Merge with e1d74a5e3226fb5b1ff4a089d4b6fd466328108e
non-jira: set release version to 8.4.2
OO-533: more context help, some small issues fixed
Merge OpenOLAT 8.4 to OpenOLAT default branch with 2bfbaad259b7bc9821636ee06bd85625037affec