Mass: use Magnum types.

src/Mass/Mass.h

@@ -18,7 +18,11 @@
 
 #include <string>
 
-enum class MassState : std::uint8_t {
+#include <Magnum/Magnum.h>
+
+using namespace Magnum;
+
+enum class MassState : UnsignedByte {
     Empty, Invalid, Valid
 };