Performance improvement to "open file" action in List filter for large files

git-svn-id: svn://svn.code.sf.net/p/autowikibrowser/code/AWB@10202 5227b50d-9349-4574-b055-4b0a7525e11c
Don't need to Close() within the using{}

git-svn-id: svn://svn.code.sf.net/p/autowikibrowser/code/AWB@10203 5227b50d-9349-4574-b055-4b0a7525e11c
Don't need to Close() within the using{}

git-svn-id: svn://svn.code.sf.net/p/autowikibrowser/code/AWB@10204 5227b50d-9349-4574-b055-4b0a7525e11c
Remove excess brackets

git-svn-id: svn://svn.code.sf.net/p/autowikibrowser/code/AWB@10205 5227b50d-9349-4574-b055-4b0a7525e11c