• manage_user_page.php: remove align="center" from td tags

• css/default.css:

  • don't make all td tags left-aligned - they default to left anyway and
    forcing it in td was preventing them from inheriting from the row style
  • make row-category headings center-aligned

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@2098 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9