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
This says "to be resurrected", but I guess we've decided there's not value in these tests now... are they duplicated?