on_mouse_leave is called for disabled Section

[discully]

If the mouse is over a Section at the moment it is disabled (Section.enabled = False), the next time the mouse is moved the on_mouse_leave function is called for that section, even though it is now disabled.

This appears to be because dispatch_mouse_enter_leave_events does not check whether the contents of self.mouse_over_sections are still valid.

I think the same would probably happen if the Section had been removed from the SectionManager.

[einarf]

@alejcas You you remember the correct behavior for this?