indent in PCH
Added unit test for #636
Added unit test for #636
Fix CSS cascade for single classes by allowing natural inheritance

We fixed this case for complex selectors earlier but missed this. Fortunately this
actually requires less work since inheritance is already handled by DTCoreText.

Also fixed the test case (the array returned with an empty line causing the test to fail).
Merge pull request #644 from amro/fix_css_single_class_inheritance

Fix css single class inheritance