ProgrammeStore getting rebuilt for simple MouseEnter/Exit events

[firthm01]

This is due to this->notifyDataChange(); in various onStateChange callbacks assigned in the constructor of ObjectView (object_view.hpp for the scene plugin)

The onStateChange callback seems to be fired for any component event, not necessarily changing its value.

Not the end of the world, but fairly inefficient

[firthm01]

I think onClick could possibly be used in place of onStateChange. onClick seems to be fired whether the control is clicked or interacted with using the keyboard.