zero-hassle runtime loading and saving of entire scenes

This package provides a framework for saving entire scenes through the use of surrogates. Surrogate classes allow special-case code to be ran during serialization and de-serialization. Surrogates can be written for any class. Associate a surrogate class with the class to be serialized by tagging the surrogate class with an attribute.

• XMLSerialization provides load and save methods for serializing any serializeable class to xml files.
• Component XMLSerializeable marks a GameObject as serializeable.
  • Upon serialization, it stores GameObject data within the serializeable class GameObjectXML, and finds surrogates for all attached components. Components without surrogates will not be serialized.
  • Upon de-serialization, the resource prefab at the path resourceID is instantiated and the surrogate is de-serialized onto that.
  • Filling out persistentID marks this GameObject as persistent, meaning it will not be destroyed before deserializing a currently loaded scene. Leaving it blank means the object is non-persistent and must be re-instantiated.
    • Persistent gameObjects are good for moving doors or GameObjects containing game logic, things that aren't intended to ever be destroyed. They do not requre a path to a resource for re-instantiation as it is expected deserializing onto the existing persistent gameobject will re-create its serialized state completely.
    • non-persistent gameObjects are good for NPCs, projectiles, or special effects. To save time, upon deserializing a currently loaded scene, all non-persistent gameobjects will be destroyed and re-instantiated since they can't be guaranteed to exist. These gameobject shouldn't rely heavily on external references to function as these are difficult to serialize.
• Component PersistentParent provide non-persistent gameObjects a parent to be instantiated onto.
  • Despite being able do so in the editor, Unity provides abosulutely no way to obtain a reliable reference to an existing GameObject during serialization at runtime. InstanceIds change every time the scene is loaded. Using an int[] to describe a GameObject's position in the heirarchy is unreliable because sibling order can change at random during runtime. There is no way to assign a persisten GUID as there is no "OnInstantiate" method and the closest method "Awake" is called every time it is loaded and the value will always be different. The only reliable way to ID a GameObject is to do it manually, and thus PersistentParent was born.