<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https://trello.com/c/evcTYKdn/219-3-adjust-out-of-date-cartridge-versions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
run gear extension ident mapping if defined
gear_map_ident function signature was incorrect
adding symlinks for phpmyadmin cart software version 3