Control activemq-rar.rar deployment via a .skipdeploy marker file

The os-eap-activemqrar module adds the activemq-rar.rar file to standalone/deployments, resulting in the rar always being deployed. But it's only useful if the server needs to integrate with an external AMQ 6 or ActiveMQ 5 broker, which with the release of AMQ 7 is becoming over time more and more of an edge case. For this reason EAP CD 13 stopped using this module, meaning users wanting AMQ 6 had to bring their own rar.

Having to bring your own rar isn't great, particular for EAP on OS 7.2, to which 7.1 users will migrate. But always deploying this rar isn't great either.

So, what we want to do for CD 14 and EAP on OS 7.2 is:

1) Always put activemq-rar.rar in standalone/deployments.

2) Always add an activemq-rar.rar.skipdeploy file to standalone/deployments.

3) Once all script manipulation of the messaging config is done (e.g. after the current messaging.sh code runs), do two checks:
a) Look for a ref to activemq-rar.rar in standalone-openshift.xml. (Meaning search for that text in the file.)
b) Look for an activemq-rar.rar.dodeploy file in standalone/deployments

If either are found, this is a signal that the user wants this rar deployed, so remove the add a activemq-rar.rar.skipdeploy file.

Note that 2a) is not the same thing as messaging.sh tracking whether its own config manipulations have added a ref to activemq-rar.rar. If the user brought their own standalone-openshift.xml and it has a ref to activemq-rar.rar then we need to detect that and enable not disable the rar deployment.