CRM-14871: Rebuild caches after extensions are upgraded in a CiviCRM-managed way (e.g., through the web UI or drush).
CRM-14871: Supply api call extension.upgrade for admins who manage extensions outside of CiviCRM (e.g., manual download).
CRM-14871 - CRM_Extension_Manager - Fix typo
CRM-14871 - CRM_Core_Invoke::rebuildMenuAndCaches - Fix regression where CiviCase XML from newly-downloaded extension doesn't get loaded.
Merge pull request #3619 from totten/master-14871

CRM-14871 - Extension & Flushing