New feature: CSS class for cells within array (flexible label) question type. This way cells within the table can have a background color assigned using CSS.
Dev: Talked to Evan so ensure the code is fine.

git-svn-id: file:///Users/Shitiz/Downloads/lssvn/source/limesurvey@7344 b72ed6b6-b9f8-46b5-92b4-906544132732