and not yet finished

semester element). Added more precise message when no resource is
available.

Fix the NPE if a single page is used to structure tests or assessment
course elements

Existing leaning resources should still work (display, copy, use in course,...)

OO-3304: Quality generator for curriculum elements should generate data collection right before its start date. Refactorings.

And implements back button in curriculum management site

Move the zoom action to the dedicated link, adn replace with a classic
select the click on title and identifier for curriculums, organisations
and taxonomy. Implements an open all / close all actions for tree table.
Add a root crumb for organisations and curriculums.