This is intended to visually separate hidden course from open courses in the course overview block
by applying a "Hidden from students" tag to the various views in this block.
To achive this, the course summary exporter's output must be augmented with a "visiblity" attribute,
carrying the given course's corresponding visibility setting.
Since the exporter now expects this data point as part of its input, the output of the course_get_recent_courses()
function had to also be augmented with the course visibility setting to provide this value.
Stefan Topfstedt
a9c3e2f95e