Reduces the the filename of logs

Using cmake and GCC, logs would contain the full file path when logging making logs lines unnecessarily long.  This is solved by just removing anything before "/Source/Core/" (where / is whatever your OS uses to separated directory).

Source/Core/Common/Logging/LogManager.h

@@ -87,6 +87,7 @@ private:
   LogContainer* m_Log[LogTypes::NUMBER_OF_LOGS];
   static LogManager* m_logManager;  // Singleton. Ugh.
   std::array<LogListener*, LogListener::NUMBER_OF_LISTENERS> m_listeners;
+  size_t m_path_cutoff_point = 0;
 
   LogManager();
   ~LogManager();