Config.has_changed didn't work reliably so far, so the state cache was
only allowing to associate a work directory with configuration file.
However this was rather unintuitive, specifically when moving the work
dir to a different home - nothing told the user about the persistent
association.
We therefore agreed to remove the state cache for now. It can be
reintroduced at any time once a consistent usage model exists.
To establish a relationship to a work directory inside a shell session,
kas now evaluates the KAS_WORK_DIR environment variable.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
