XD-2237 add python module for implementing processor
XD-2237 removed stray .pyc and __init.py
XD-2274: Intermittent TcpModulesTests testTcpSink

Introduced usage of EventuallyMatcher for tcp sink output.
Merge branch 'XD-2237' of https://github.com/dturanski/spring-xd into dturanski-XD-2237
Merge branch 'dturanski-XD-2237'
Test cases asssociated with the commit validates Py code changes.
Ran through full test execution from this branch; test build successfully completed.
Merging to master.
Merge branch 'master' of https://github.com/spring-projects/spring-xd
Fix ShellCommandProcessorTests
  - Fix echo.py stream python module path
XD-2239 Make container IP/hostname configurabale

* Make the container IP address configurable
* Make the container hostname configurable
* Add tests

XD-2239 Code Review changes
XD-2239 Fix container host key
Fixed ShellProcessorTests redux
XD-2238: Improve module deployment distribution

Introduced a "quiet period" property. The quiet period is the amount
of time that must elapse after the newest container arrives before
deployments to new containers are initiated. A short quiet period
is ideal for development environments because it results in quick
deployments to new containers. In production environments, longer
quiet periods are desirable because it will prevent the first few
containers from receiving all deployments.

Note that this property only applies to module deployments to new
containers; deployments initiated to existing containers are not
subject to delays.

When new containers connect to ZK, module deployments to the
new container are scheduled on the same executor service that
is handling all module deployments. If new containers arrive
during the quiet period for the first container, the deployment
will be rescheduled for the quiet period after the newest container
arrival time.