OO-1620: add modifier informations if available, add publication and modification item if in the time frame of the notifications

OO-1620: mark as new podcast and blog, rewrite part of the notifications handlers, fix some issues reading the ids of the publishers

OO-2784 optimize sections, add item id (hidden), compile offline files for download, beautify coach comment

OO-2790: implement persistence of panel open/close for QTI 2.1 and comment, disclaimer, results and asssessment documents

OO-2790: add the options to upload assessment documents on a per course element / user base which behave like the user comment

OO-2742: reimplement start option (without autoplay), host in openolat flv.js and hls.js to prevent url with http/https blocked by Firefox, enhance useability of chapter editor

OO-2791: show an error message if a question of the pool is not readable during the import in a test