And make the mapper of the auto completer static

Allow the browser to cache the images in the page editor (new images
will get new mappers and therefore update is not an issue), don't create
new image component by settings changes but update them to allow again
the browser to use the cached images.

Only set the mapper encoding if it's really found (in the case where it
is not defined by the configuration), don't set it with a default one,
use only the default to deliver the media resource if needed

Randomize the delivery of SCORM files for authors and reload the content
after the settings have been changed to propagate quickier changes like
encoding and make them effective

Reviewers with comment permission are allowed to see the self evaluation
of the user which gave them the permission. Assignment with "Only self
evaluation" doesn't have and doesn't need the option "Invitee can see
self evaluation"