dataTables.jqueryui.scss not included in build?

I've used NuGet to add DataTables 1.10.0 to my VS 2010 project. It works fine, but I just noticed that the file dataTables.jqueryui.scss is missing from my production site. In VS, the build action for this file is "None", while the other css files have "Content".

I assume I can just change the build action, but:

1. Is it a bug that should be fixed in the NuGet package?

2. If not a bug, is it as designed, and then why is it not included in the build?

3. If not a bug, did I screw it up somehow and should add it (as "Content")?

4. What is the purpose of this file?