#1 Handle Course access list

[Hugues Pisapia]

It's been requested to selectively release the availability of the Voice tools
and Live Classroom to only approved courses.

This item could be enabled in the configuration Panel of the tools and
then the administrator would have to enter the list of courses that would
be allowed to add the tools as activities.

When a teacher tries to create a tool and is not allowed, he will receive an
error message explaining that the course is not yet allowed.