Optimized the database query in file_list_attachments()
It now specifically lists the columns it uses instead of using *
This improves performance noticeably in bugs with large attachments since no
longer is the whole attachment content fetched when listing filenames.

Modified Files:
core/file_api.php doc/ChangeLog

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@2191 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9