XD-1139/1140 Initial Commit

For initial review (but functionally complete).

This is pretty cool stuff - probably a good place to start is `RemoteFileToHadoopTests` - it runs the job which fetches two files from a (mock) ftp server, and dumps their contents into hdfs in parallel.

- Partitioner
- Tasklet
- Job Configuration (FTP)

TODO: Full blown JobPluginTest
TODO: Parameters definition
TODO: Docs