Removed custom_config_inc.php as a possible config file after discussion with Victor and Julian. I decided not to support it either, to limit the files that we have to check, since there should only be a handful people using it

git-svn-id: http://mantisbt.svn.sourceforge.net/svnroot/mantisbt/trunk@1875 <a class="text" href="/?p=mantisbt.git;a=object;h=f5dc347c">f5dc347c</a>-c33d-0410-90a0-b07cc1902cb9