Replace the old course/dragdrop.js file (which was not even minimised)
to AMD modules and integrate them to the new reactive course editor.
From now on, a file can be drop over any course section, no matter if it
is in the course content or in the course index. It will also start
using the new process monitor to show the uploading state to the user.
Move the section visible logic to the format base class. This way format
plugins can decide whenever a section is visible or not instead of using
format custom settings from core.
Ferran Recio