FXOLAT-504: missing i18n key, beautify the publication date in metadata of file, some changes in ful text search...

OO-1770, OO-1769: allow pseudonym and guest posts, refactor the message model to hold only threads or messages of a unique thread in memory, minimize the number of joins on query, minimize the number of queries on peekview, remove buggy docking feature...

OO-1658 implement HelpTooltip componente to use the new form context help also outside of the form context

OO-1741 remove ? from dummy avatar images, adding anonymous avatar and removing old avatar images outside the theme

OO-1739: backport the delete button in file element and use it in user profil for the avatar, in the resource description and in the catalog entry editor

no-jira: beautify the list of sub levels in the catalog if the number of levels is uneven and the view of type list

OO-1645: add sort, add feed for imported calendar, fix visibility of imported calendars right after import, fix ids of imported calendars

OO-1645,OO-1595: refactor the personal configuration of calendars, the datamodel of imported calendars, make the description visible and editable...

OO-1647: remove auto-subscribe of course calendar, list of course which the user is member of and which have a calendar ( as configuration or as course element)