Update logging system

- Update to fmt 6.0.0
- Updated logging system to be macro based
- Fixed a bug with including

src/common/logging/log.cpp

@@ -0,0 +1,18 @@
+// Copyright 2019 threeSD Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <chrono>
+#include "common/logging/log.h"
+#include "common/string_util.h"
+
+std::uint64_t GetLoggingTime() {
+    static auto time_origin = std::chrono::steady_clock::now();
+    return std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::steady_clock::now() -
+                                                                 time_origin)
+        .count();
+}
+
+std::string StandardizeLogClass(const std::string& log_class) {
+    return Common::ReplaceAll(log_class, "_", ".");
+}