Fix for {{page needed}}

git-svn-id: svn://svn.code.sf.net/p/autowikibrowser/code@10476 5227b50d-9349-4574-b055-4b0a7525e11c
List comparer: only enable Compare button when at least one article in each source list

git-svn-id: svn://svn.code.sf.net/p/autowikibrowser/code@10477 5227b50d-9349-4574-b055-4b0a7525e11c