* Instructions on how to perform H2 DB upgrades without starting the node.
* Formatting error. Adds required subsections in H2 docs.
* Merges duplicated information about H2 DB access.
* Drops script references for now.
* Clarifies upgrade notes.
* Better title.
* Inr
* Addresses review comments.
* Addresses review comments.
Set the "h2.allowedClasses" system property, require database password when exposing H2 server on non-localhost address, samples start H2 server by default (reintroduces the behaviour before h2Settings.address configuration option was added)
