Minor changes to math module

-Fixed missing Set method: "X::Set(const X&)"
-Removed operator String


Former-commit-id: 690f161704ed85fc57a62b812af7933e390572b5

include/Nazara/Math/Matrix4.hpp

@@ -84,8 +84,6 @@ class NzMatrix4
 
 		NzMatrix4& Transpose();
 
-		operator NzString() const;
-
 		operator T*();
 		operator const T*() const;