Enable BatchInitializer by default

- Provide option in xd-config.yml to disable batch initializer
- Remove initializeDatabase flag from application.yml
Update spring-xd-yarn xd-config.yml

- Update batch initializer config in spring-xd-yarn's xd-config.yml
   - Have it commented out by default
Set the contextPath to "".

Jolokia currently doesn't work if contextpath is set to /management.
Once XD-1494 has been resolved by Spring boot 1.2.1, we will need to set the
context path back to /management.
Enable parallel tests

- Modify RandomConfigurationSupport's deleteFiles to print stacktrace in case of failure while
deleting
- Increase `forkEvery` to 20 in case of spring-xd-shell
- Running -PmaxParallelForks=<?> improve build time depending on the dev machine configuration
XD-1488: Add test for module environment insulation
Reverted one change from "Fix some compile warnings"
XD-1508: All jobs end up on the same container

Modified job deployments to use ContainerMatcher
(similar to stream deployments) instead of creating
a new iterator from ContainerRepository on every
job deployment.
Provide explicit contextId for AdminServerApplication

- Add AdminIdInitializer that sets the adminContextId explicitly
Override XD MBean exporters' domain names

- Exclude JmxAutoConfiguration so that Integration MBean exporters defined in configuration classes based on the conditional
expression ${XD_JMX_ENABLED:true} get to set their domain name
  - With this change,
     - the XD container will have MBeans with domain names `xd.parent`, `xd.shared.server` and `xd.container`
     - the XD admin will have MBeans with domain names `xd.parent', `xd.shared.server` and `xd.admin`
     - the XD singlenode will have all the MBeans above
XD-1378b: Remove PPC from twitter*
XD-1378: Update tweet_tests

Property file locations have changed.
XD-1482 initial support for deployment manifest

Currently supports two manifest keys:
  1. module.[modulename].count
  2. module.[modulename].target.group
addressed review comments
added javadoc to loadStream()
using target SpEL expression for container matching
renamed manifest to properties
added WARN for no match, and removed WARN that was accidentally left behind
fixed JobListener compiler error after rebase
flipped (to align correctly) values in log statement
avoid NPE on AdminServer ZK disconnect