Avoid Java7 System.lineSeparator()
XD-1359 Added EmbeddedZooKeeper

Added ZooKeeperConnection and ZooKeeperConnectionListener

Moved ZooKeeperConnection bean to the ParentConfiguration

EmbeddedZooKeeper determines available client port on startup

Updated per review comments
File.pathSeparator -> File.separator
XD-1190: Provide defaults as type.module.option

Remove @Value/@PropertySources support

Rename DefaultsProvidingModuleOptionsMetadataResolver to EnvironmentAwareModuleOptionsMetadataResolver

Make our PropertySource the only one

Add integration tests that check defaults order

Address ordering review comments
XD-1319: Allow mixins of Pojo Metadata
XD-1343 Added XD extension mechanism
XD-1343 changes per review comments