XD-1686: Pluralize admins group node

- Since we support multiple admin servers and all of them participate in leadership election,
it might be good pluralizing the leadership group path's node name

/xd/admin -> /xd/admins
XD-1504: Avoid duplication when loading streams for deployment

Introduced class DeploymentLoader to handle the loading of
streams and jobs for deployment. It also includes the loading
of deployment metadata.

Eventually this should be merged with the various ZooKeeper
implementations that work the same. For now this was created
to eliminate duplication between ContainerListener,
JobDeploymentListener, and StreamDeploymentListener.
XD-1575

Fixes XD-1575 by adding support for UDP to the SyslogInboundChannelAdapter. Internally it forks on the Tcp/Datagram configuration depending on the value of the "transport" configuration option. The test was updated to run the TCP tests by default, since they are the only ones that can be run reliably on CI servers. The same tests can be run in UDP mode by specifying -Dtransport=udp on the command line when running the tests but they must be run manually because the tests assume that all messages reach the destination which is not a guarantee with UDP so there's no way to reliably test whether messages were properly sent or not.

XD-1575 updates Reactor to version 1.1.0.RELEASE

XD-1575 minor tweaks
XD-1630: Cut dep from xd-shell to xd-dirt
XD-1536: Updated pre-packaged jobs to allow a delimiter to be injected
where apropriate
* Updated configuration of filejdbc, hdfsjdbc, hdfsmongodb, and jdbchdfs
 jobs to allow for the delimiter to be injected
* Added BatchJobFiledDelimiterOptionMixin to provide metadata around
 new delimiter option
* Updated jdbc_tests script to test the processing of a job using a tab
 as a delimiter.
XD-1685 Rabbit source Acceptance Test
RabbitSink Acceptance Test now available.

Code Review Changes