This commit adds a strategy interface to specific if a given DataSource
has its schema managed. The Hibernate auto-configuration uses it to set
it to "none" if a mechanism to initialize the DataSource is
found and "create-drop" otherwise.
Both Flyway and Liquibase implements that strategy interface and
register it in the context accordingly.
Closes gh-9262
If Liquibase is on the classpath it will fire up on startup. Various
config options are available (as well as the option to disable it).
Liquibase uses a YAML format for changes (in classpath:db/changelog).
Andy Wilkinson
Stephane Nicoll
Phillip Webb
Madhura Bhave
Vedran Pavic
Phillip Webb
Marcel Overdijk