Added Entityx to project

external/entityx-1.1.2/cxx11/c++11-test-cstdint.cpp

@@ -0,0 +1,10 @@
+#include <cstdint>
+int main()
+{
+	bool test = 
+		(sizeof(std::int8_t) == 1) &&
+		(sizeof(std::int16_t) == 2) &&
+		(sizeof(std::int32_t) == 4) &&
+		(sizeof(std::int64_t) == 8);
+	return test ? 0 : 1;
+}