OO-3087: cancel the search if timeouted, make the timeout configurable, reduce it to 15 seconds, implement it for spell checker too

OO-3087: add a timeout to the full text search requests, free the DB connection before doing the search

OO-3076: use the max. number of uploadeable documents from submission settings as default in the revision process

OO-3067: Handle exception if a course reminder rule is invalid and add some validations in GUI to avoid invalid reminder rules

OO-3058: disable the optimistic locking by efficiency statement and replace with last commit win (in all case, the last which compute it win, locking or not)