MH-8641 -- Added logging in case of missing whiteboard implementation

git-svn-id: http://opencast.jira.com/svn/MH/trunk@13557 e6edf6fb-f266-4316-afb4-e53d95876a76
MH-8889 -- commented out lines in config.properties that will work with defaults

git-svn-id: http://opencast.jira.com/svn/MH/trunk@13558 e6edf6fb-f266-4316-afb4-e53d95876a76