Xd 1517

This PR addresses XD-1517 (removing _deployments URL) by providing separate endpoints /deployments  and /definitions for streams and jobs. Some related changes are:

(also applies to Jobs)
deploy is a POST to /streams/deployments  instead of a PUT to /streams/{name}?deploy=true
undeploy is a DELETE /streams/deployments/{name} instead of PUT /streams/{name}?deploy=false
undeploy all is DELETE /streams/deployments
Yeah, this one is a tough call. If we did not know the resulting url of the deployment beforehand, this would be a no-brainer I guess: POST to /deployments and get back a resource that says that the deployment sits at /deployments/foo

But given that we DO know it, it's a bit more complicated. OTOH, what we are doing is creating a "deployment for foo" (NOT a deployment that is "named" foo). So the "collection" is itself "/deployments/foo/", it just so happens that there can be at most one for a given stream.
So I would vote in favor of POST on /deployments/{name} as well