Please tag and release as 7.x-2.0-beta8

Updated installation profile to 7.x-2.0-beta8
PT-831 - Updated the Petitions installation profile to build with Drupal core 7.21
PT-873 - Removed clean_mongo, clean_mongo() calls, and added requirement for Mongo 2.2.4.
PT-876 - Updated petitions_data to include an admin form to set base URLs to be used when generating links
PT-878 - Updated shunt module to implement shunt_enable() and shunt_disable() as described in README roadmap, enable a drush interface, and update the configuration path. Updated shunt_api module to prevent memcache problems when shun