OO-613: unify Onyx QTI 2.1 tools with the OLAT QTI 1.2 tools to remove duplicate code, change the WebService stack for Onyx

OO-530: replace HashMap with ConcurrentHashMap in some critical places where multi threading is an issue

OO-433,OO-441: optimize data retrieval, save default values of properties which doesn't exist, check if the table controller is not disposed after loading start the data

OO-373: made the notifications manager robust under concurrent access, write more unit tests to tests the queries on the database and test it under concurrent load

OO-291: first step: move business gourp manager to a business group service, remove dependency to the context...

OO-170: refactoring of the property table, move efficiency statements and initial/recent launch dates to their own table

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branch : 80-patch

OO-15: set last update and initial launch date invisible as default, add table configuration for Node > User in Assessment Tools

--HG--
branch : bps

--HG--
branch : uzh72backport