Fixed 2717: Where a bug could be submitted or update to have empty summary /
description fields. The fix included added validation in bug_create() and
bug_update() to reject submits/updates with empty trim(summary) or
trim(description).

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@1621 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9