<upgrade.rb, phpmyadmin cart> Update phpmyadmin manifest, tweak upgrade.rb to use the new manifest for IDENT
https://trello.com/c/evcTYKdn/219-3-adjust-out-of-date-cartridge-versions

Modified upgrade.rb to use the next_manifest when calculating the
updated IDENT info

Updated version numbering in phpmyadmin manifests to avoid display of
minor version number, per linked trello card