Make various operations idempotent
Make various operations idempotent

- adding of RabbitMQ vhost and user
- starting of services

aplanas/crowbar,crowbar/crowbar,dirkmueller/crowbar,SUSE-Cloud/crowbar,nkrinner/crowbar,rhafer/crowbar,rsalevsky/crowbar,toabctl/crowbar,rsalevsky/crowbar,nkrinner/crowbar,mmnelemane/crowbar,tserong/crowbar,aspiers/crowbar,rhafer/crowbar,aplanas/crowbar,MaximilianMeister/crowbar,rhafer/crowbar,vwallfahrer/crowbar,SUSE-Cloud/crowbar,crowbar/crowbar,mmnelemane/crowbar,vwallfahrer/crowbar,dirkmueller/crowbar,toabctl/crowbar,tserong/crowbar,aspiers/crowbar,MaximilianMeister/crowbar