chimera: Optimize schema migration

Also add empty rollback rules to allow the schema to be downgraded.

Target: trunk
Require-notes: yes
Require-book: no
Acked-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>
Patch: http://rb.dcache.org/r/6494/
spacemanager: Fix option value in ls files command

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/6495/
spacemanager: Fix expiration check

A small bug sneaked in when changing lifetime to expirationtime.

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/6496/
Revert "chimera: Optimize schema migration"

This reverts commit ee2a4ad9e73309721d68a19cbf0b7de5d57500e2.
Merge branch 'master' into 2.8-ndgf
[maven-release-plugin] prepare release 2.8.0-rc3+ndgf
[maven-release-plugin] prepare for next development iteration