Ensure block info cache is not stale after administrative actions alter block info (e.g. creating new views)

Reduce the number of calls to drupal_alter() - move alter from property fetch event to context_load().

#781792 by vectoroc: Ensure default roles are localized properly before checking user role condition.

Removing redundant implementation of hook_flush_caches() and removing hook_features_api() -- moved back into features in http://drupal.org/cvs?commit=337700.