XLCLOUD-1666 - Use RabbitMQ connector instead of Stomp for mcollective transport

Modify MCollective broker template.
XLCLOUD-1666 - Use RabbitMQ connector instead of Stomp for mcollective transport

Rewrite templates to remove references to Stomp connector.
Use F19-x86_64-xlcloud image by default
XLCLOUD-1565 - Design and develop an ohai plugin for XLcloud

Update slurm and ganglia layers after mcollective cookbook refactoring.
Minor changes to mcollective-broker.template
Update SLURM stack

Pass broker paramters to template and layers
Refactor runlists and move stuff to Chef roles
Add ohai facts file