Allow drush to work when in the islandora_solr module directory.

When looking back up the filesystem, Drupal bootstrapping hits a false
positive (http://drupal.org/node/1481270#comment-6585758 gave me the
clue)... So yeah, don't create an "includes/common.inc".
Merge pull request #125 from adam-vessey/7.x-fix-drush

Allow drush to work when in the islandora_solr module directory.