(#22324) Reset confine method to confine_block

confine_block is defined in my fork of Beaker.  confine will work here,
but only be accident, because a block passed to the confine method is
expected to further refine acceptable hosts.  confine_block just uses
the criteria to refine hosts and then executes the block on those hosts.

This commit is only in the integration/acceptance branch until we get
that merged in.
(maint) Ignore repo-configs directory

Just has locally stored repository information for acceptance runs.
(maint) Don't require CONFIG

It can be set in the local_options.rb as well.
(maint) Rake task to clean up preserved hosts.
(maint) Add configuration to run all the linux nodes
(maint) Manually archive hosts_file in log/latest/config.yml

Beaker is no longer archiving the current hosts configuration as
log/latest/config.yml.  So we are doing this ourselves if the current
run is preserving hosts.