Compatibility with JVM snapshots (OpenJDK's Project CRaC)

[rwinch]

As a project wide initiative the portfolio is looking into support for Project CRaC which allows JVM snapshots to be taken and then restored for faster startup times.

We will need to ensure that file handles are closed which are:

• Database connections (likely to happen in Spring Framework)
• LDAP Connections (likely to happen in Spring LDAP)
• Ensure we update to the new Lifecycle methods proposed in Spring Frameworks support.