Rudder

When trying to set up a full dev environment based on Vagrant VM, we are limited by tests made by CF-agent on the rudder server VM, particulary the fact that there is a test to see if rudder-webapp is up and running.

Of course, that is not the case in dev set-up, snice the webapp is running on the host (dev) machine, and so, CFEngine always restart Jetty.

That leads to other problems, like #2630.

So, it would be great to have a test made in server promises (for example, on the existence of a specific file, like /etc/rudder/this_is_a_dev_server) and if that test is passed, then some check are not made.