FIXED: [Migrations] assert protobuf-c, json-c, fstrm packages available before applying October migration. CHANGED: [Bootstrapper] Package scripts may pass "yum_transaction_hook" variable to inform Bootstrapper if scripts are running from within Yum transaction. Resolves a potential deadlock if an included tag calls yum during transaction. [PHP] Automate recovery if apache,webuser system user is missing from /etc/password. [UI] "Use External Opener" feature always appends to URLs that match ^http.