JetBrains/kotlin — pull request #235 by leftylink (2013-03-29 16:52:25+00:00)
Title: Implement quickfix for MANY_CLASSES_IN_SUPERTYPE_LIST

Tweaks to invoke() method of https://github.com/JetBrains/kotlin/pull/234

This uses existing utility method PsiImplUtil.skipWhitespaceAndCommentsBack to look for previous comma.
Checks that the node found truly is a comma before deleting.