XD-987: HDFS to mongo export job

Create
  - spring-xd-extension-mongodb
  - hdfsmongodb module

Move existing mongo code from hadoop extension to new mongodb one.
Add new TupleItemWriter which allows a specific identity field to be
chosen if required instead of the generated Tuple UUID.
XD-988: Batch export from HDFS to JDBC.

Note the issue with Spring HADOOP (SHDP-201) which prevents the easy use
of both HDFS and file resources in the same module, thus preventing the
use of the same DB initialization code from the file->JBDC module. This
is commented out for now and relies on manually pre-creating the
database table.
cleaning up redis keys for composed module
XD-282 Dataset support to store POJOs with Avro

(first iteration)

polishing/formatting on merge
XD-282 Adding an avro sink

(similar to the hdfs sink)

- adding parser and integration tests
- enabling the HdfsOutboundChannelAdapterIntegrationTests using filesystem for Hadoop FS

formatting xml for avro sink
Initial impl: profiles and interpolation
Add logic for simple ModuleOptions
Introduce ModuleOptionsFactory and POJO stub
Add module info command
Naming refactorings
Actually pass props through at deployment time.

Also, apply to file sink.
Add POJOModuleOptions
Load options class using the module ClassLoader
WIP Gemfire profile activation
Implement profile activation, use it on Gemfire sinks
Use converter for Module definition download