We rescue 'LoadError' in Manager

Let's raise OxidizedError instead for known dependencies
run cmd :secret blocks if CFG.remove_secret is set

Model can inmplement something like

cmd :secret do |cfg|
  cfg.sub! / secret (\d+) (\S+).*/, '\\1 SECRET'
  cfg
end

Which is called for all commands if CFG.remove_secret is set