Added basic compile support for MSVC 2013 to byte.

tests/byte_tests.cpp

@@ -87,6 +87,7 @@ SUITE(byte_tests)
         CHECK(a == byte(0x0F));
     }
 }
+
 }
 
 int main(int, const char* []) { return UnitTest::RunAllTests(); }

tests/span_tests.cpp

@@ -794,6 +794,15 @@ SUITE(span_tests)
         CHECK(it1 == it2);
     }
 
+    TEST(const_iterator)
+    {
+        span<int>::const_iterator it1;
+        span<int>::const_iterator it2;
+        CHECK(it1 == it2);
+
+        
+    }
+
     TEST(begin_end)
     {
         {