Support old prefab system

Added support for the prefab system used before Unity 2018.

Assets/MA_ToolBox/MA_TextureAtlasserPro/README.md

@@ -1,21 +1 @@
-# MA_TextureAtlasser
-Texture atlas creator for Unity
-
-[![Image](https://maxartz15.com/wp-content/uploads/2019/04/MA_TextureAtlas.png)]()
-
-You can combine textures and/or remap the UV’s for the 3D models.
-By having full control over the size and position of the textures that are being placed in the atlas you will never stand for surprises when exporting. This will cost some more time than auto-generating your texture atlases but you know whats going on and which models/textures are getting priority. The tool can also be used to make 2D sprite sheets.
-
-- Combine textures/sprites.
-- Automatically adjusts the UV's of the assigned meshes to match the new texture atlas.
-- Exports meshes as OBJ.
-- Exports texture atlas as PNG.
-- Exports texture atlas as a (sliced) sprite sheet.
-
-[Example video](https://youtu.be/PBRKlopkZP0)
-
-Download the UnityPackage here: https://github.com/maxartz15/MA_TextureAtlasser/releases
-
-[![Github All Releases](https://img.shields.io/github/downloads/maxartz15/MA_TextureAtlasser/total.svg)]()
-
-For more information: https://maxartz15.com/ma-textureatlasser/
+README: https://github.com/maxartz15/MA_TextureAtlasser/blob/master/README.md