easy and stable upgrading

[fbstj]

one practical request would be for the workflow around our actual instance with all our books and etc to be as easy and well documented as possible to maintain and upgrade, as untechnical or time-squeezed maintainers may be involved.

would be super awesome if it was one-click backup & migrate with update detection from the admin dash but we'd definitely settled for a well explained and infallible command like process to start with