HW5 grading.

If you got the following working correctly, then your minimal grade is 
about...

* Ambient Shading - 7/15
* Multiple lights - 9/15
* Ambient and Multiple lights - 13/15
* Mirror surfaces and the rest - 15/15

Things people missed (besides not doing the mirror)...
* if using new to create lights, need to delete in the descructor
* ambient light should apply to things in shadow
* things in shadow of one light can still be hit by another light