Application $conf['home'] should be included in the default settings

Needed by the application and we must make sure it is there.
Anyone that does not like this can locally override this settings.
One less settings that needs to live in settings.inc.php.

common.inc.php

 <?php
 
 $conf['version'] = '20130612';
+$conf['home'] = LOADSPEAKR_ROOT . '/';
 $conf['output']['select'] = 'json';
 $conf['output']['ask'] = 'json';
 $conf['output']['describe'] = 'rdf';