Make migration basis to be configurable

Keep deafult as "consensus", but make it configurable with params.
Default is a little bit hacky, as it is not clear from template
how it changes.
Make clientIdPolicy and subscriptionSharingPolicy configurable

If they are not set, do not try to set values as in old implementation.
Display more error parameters

Just join every item.
Try creating bootstrap file after activation

For some reason this seems to fail, so ignore failure.