OO-623: check more places where authors can create groups as enrolment and contact course building block, visibility access rules and course preview form

CL-232: enhance REST API to manage calendar events in a course, hardened login filter against concurrent startup, add headers

OO-684 fix left alignment in trees with root, add marker css to tree, more general defaults in definitions

non-jira: fix js errors in translation tool due to prototype->jquery migration, adding some i18n keys

OO-623 adding more context help for managed flags, translating managed flags in GUI for courses and groups

OO-623: fix some issues with display of lifecycle in details, fix wrong display in the select box in edit properties of course

OO-533: fix RS by bulk change if no item is selected in the details view, fix flexi table "0 showing 0", fix error search, add Indexer to probes

OO-533 UI tune the pool admin area, adding i18n intro help texts, new css classes to make master-detail view with menu panels

OO-682,OO-531: remove sound for new message on IE as it create an error or show a big play button which results that we cannot open the instant message window

OO-681: enhance the XSL stylesheet which outputs the results to handle interval of values as correct answer

OO-532: fix the callout which stay on the top left of the window after switching the view from month to week and so on

OO-533 various layout improvements question pool, streamlined highlight color in table, calendar and buttons