Add a script to migrate 6.0.8 from serial to DB

[mdhafen]

Add a script, targeting Pydio 6.0.8, to migrate from auth.serial and conf.serial to auth.sql and conf.sql.

This pulls as much information as possible from the Serial plugins for auth and conf, and recreates that information in the sql plugins. This then allows people to upgrade their Pydio installs past 6.0.8 if they are using the Serial plugins.

Generating pull request as advised in the Forum: https://pydio.com/forum/f/topic/serial-to-sql-migration-script-for-6-0-8/