Send clear message to the class (and in particular to the teacher Class Views) when a new activity is started (i.e,. on Send View)

[cbradyatinquire]

When the teacher in Designer creates an activity and sends it to students (either to the whole class with Send View to All or to selected groups with Send View), we want the Class View windows to receive a CLEAR message before they receive the new activity's GeoGebra objects. That way, they will be in sync with the students.

Right now, they don't get a clear, so the objects from before the activity stick around in the Class View.

[cbradyatinquire]

(this issue was necessitated by doing issue #49 , which is GREAT but has this problem)

[thompchr]

This could actually just be an internal call within the admin/teacher view to reset all of the applets that are affected to the activity's base state