non-jira. center thumbnail preview image in folder pdf preview when title is longer than image width

OO-2057 fix more nullpointers when no binder and sections is available, styling ep start page, entries listing, binder listing, adding de translations

OO-2057: adapt the course element for the new binder, the assessment tool to view the details of the new binder and the binder resource

OO-1593: implements drawing interaction, fix in table search in assessment tool, fix statistics in course overview of the assessment tool...

OO-1867: upgrade selenium and arquillian libraries to support Firefox 46 and update the tests to work with them

OO-1593: adapt qtiworks to our way to work with essay,  fix feedback for hotspot and other small fixes

OO-1593: add more informations for unkown interaction in editor, add debug informations in the preview of the item's editor (for openolat question types and the others)...

OO-1593: use a composite id instead of the responseIdentifier in the GUI, this will allow to show the response of the user and the solution of the same interaction side by side

OO-725 use title and desc from repoentry instead of own one, move files from media to master dir, bautify runtime, reload root controller on breadcrumb-click

OO-725 implement copy of resource, beautify caption chooser, fix controller leak, reload transcoding list on segment change

OO-725 update to mediaelementjs 2.20.1, implement GUI prefs to store user preferred resolution, implement sourcechooser in player