• core/icon_api.php
  (print_sort_icon): accept ASC and DESC constants as well as the strings
  'ASC' and 'DESC'

• core/print_api.php
  (print_manage_user_sort_link): accept ASC and DESC constants as well as
  the strings 'ASC' and 'DESC'
  (print_manage_project_sort_link): accept ASC and DESC constants as well
  as the strings 'ASC' and 'DESC'

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@1816 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9