Fix installation problem using make file, due to Drupal.org upgrade.
See https://github.com/drush-ops/drush/issues/234#issuecomment-27631773
Issue #4180: Update OG-Vocab to latest release, which also fixes installation via UI.
Merge branch 'SCHOLAR-3.x' of github.com:openscholar/openscholar into SCHOLAR-3.x