Editor for Milestone 2: More Basics

[MoloAdrian]

All Editor changes

• Add space types to editor to be able to set space to different types (this resets the space cameras to initial values of each space).
• Add audio sources as engine components (add audio listeners too but check if it already exists one as only one audio listener is allowed per scene [This can be checked with the soundmanager, storing the audio listener in that class and if it exists then don't add it to new objects]).
• Add prefab and archetype load and save to editor
• Change play text to say stop when the editor is playing (and set back to play when stopped). Also, don't reset the editor camera everytime it is stopped.
• If in a 2D space, don't let UI images set any model, just the texture.