Make the compiler to support super.X/L.super.X which access super class' fields....

Make the compiler to support super.X/L.super.X which access super class' fields. We might still not be able to correctly support access to super class' methods like super.foo(). Also fix another nested class bug. Previously the unit test StaticInnerClassTest was broken because of newly added inner class support. Note that nested class (static inner class) should NOT have reference to its surrounding class in its constructor as it is static and can be created without any outer class instance.