I have some files which are not normal resources. Like odd file extensions (not txt or jpg etc.). I want to make sure they get copied to the ‘data’ folder when the game gets built. I was hoping I could just put them in Resources or Plugins but that’s not working. Can I do this easily, or do I need to write a custom editor script to build and copy?
Well 3.5.2 gave me just what I needed: http://docs.unity3d.com/Documentation/ScriptReference/PostProcessBuildAttribute.html
Unfortunately there is no delegate or callback when the building process has finished (at least non that i know).
You can however use a Perl script that is executed after the build. See PostprocessBuildPlayer
edit If you have Unity pro i guess it should be possible to just write an editorscript which creates the build manually. See BuildPipeline