Append a new LogOutput class, it's style like Java on Android.

inc/hgl/log/LogLevel.h

@@ -0,0 +1,14 @@
+#pragma once
+
+namespace hgl
+{
+    enum class LogLevel
+    {
+        Verbose,
+        Info,
+        Hint,
+        Warning,
+        Error,
+        FatalError,
+    };//enum class LogLevel
+}//namespace hgl