Added Exceptions to the System.Xml library
Added missing DisplayModeCollection class
Added Stack class (will be tested soon, and removed again if it doesn't work)
* This revision's libXFX doesn't build. This is due to the List template not handling pointers to abstract classes the way I'd like it to do. Need to look into.
Now, the only thing keeping XFX from a full compile is my stupid attempt at Asynchronous IO. Will look at that, but most likely, I will comment it out and just get a new Demo out before New Year.
