XD-1590: Move ephemeral nodes to /xd/deployments

In order to have a clearer separation of definition vs runtime
information, the ephemeral nodes written by containers were moved
from /xd/streams/stream-name to /xd/deployments/streams/stream-name.
Same for jobs.

The work of building these path streams falls under StreamsPath and
JobsPath. These classes were renamed to StreamsDeploymentsPath and
JobsDeploymentsPath, respectively.

Class DeploymentVerifier was introduced into the test package. This class
is used to block execution until a stream or job is created, destroyed,
deployed, or undeployed. Instead of extending this class, stream and
job path information is provided via the DeploymentPathProvider interface
which is passed along to the DeploymentVerifier constructor. A new
exception type RuntimeTimeoutException was introduced in order to
indicate a timeout. This is a runtime version of TimeoutException which
is a checked exception in the JDK.

In SingleNodeIntegrationTestSupport, if a PathChildrenCache object is
created in addPathListener, the listener is added before invoking start
to ensure that no events are missed.

In ContainerRegistar, a subtle race condition was fixed in
registerWithZooKeeper. The admin leader/supervisor will delete nodes from
/xd/deployments/modules/[container-id] for containers that are not present
under /xd/containers. Therefore if a new container creates a
.../deployments/modules node before creating its /xd/containers node,
the leader could delete its deployments node. This has the nasty side
effect of rendering any PathChildrenCache instances for the deployments
path useless since it won't receive events from a path that is deleted
and recreated.

StreamListener now offloads module deployment and undeployment via a
dedicated thread in order to prevent the Curator thread from being
blocked. We might consider making the executor service multi threaded
at some point if there is a benefit.

ZooKeeperStreamRepository will delete the data under
/xd/deployments/streams in the order in which the stream modules were
defined. This allows for an orderly undeployment of streams. It is obvious
that the source should be undeployed first and the sink last. Other than
loading the stream definition itself (and parsing it, etc) the only way
to know what order to undeploy the processor modules is to examine the
order in which they were deployed. This can be done by examining the
ZooKeeper transaction id as all writes in ZooKeeper are ordered.

Some of the test asserts were enhanced with extra debugging information
to assist in test failure analysis.

The default timeout in DisposableFileSupport was reduced from 10 seconds
to 1 second. This was done because the asserts that use this class all
use the "eventually" matcher which executes underlying matchers multiple
times. For tests that fail due to a module deployment issue and thus
preventing the expected file from being created, this combination would
cause the tests to execute for a very long time before timing out. In
fact this condition could be easily mistaken for a "hung" test.

On a related matter, the defaults for EventuallyMatcher were reduced
from 50 tries to 20 tries.