* Refactored achievements to utilize C++ features
* Cleaned up the YAML parser.
* Moved achievements from DBMap to an unordered_map.
* Moved achievement targets from DBMap to a vector.
* Changed all struct arrays into vectors.
* Changed all char arrays to strings.
* Changed all int arrays to std::arrays.
* Removed achievement_dummy as it's no longer needed.
* Achievements now use smart pointer to ensure proper construction and deconstruction of objects.
Thanks to @lighta!