Fix hdfs import tests.

Match change in option name 'columns' -> 'names'
XD-1200 Fixing hdfsjdbc job configuration in test script
XD-1186: Support for overriding application.yml

Use Spring Boot's spring.config.location option to point to an additional
configuration file which can be used to override the defaults.

Introduces XD_CONFIG environment variable which defaults to
config/xd-config.yml in the startup scripts but which a user can set to
point to a filesystem location outside XD if they wish.

The file config/xd-config.yml is commented out by default so has no effect
unless edited.
XD-1186: Support for overriding application.yml

Changed xd-config.yml to include ready to uncomment config snippits for
the database, redis and admin UI.
XD-1200 Fixing hdfsjdbc job configuration in test script
Merge branch 'tekul-XD-1186'
XD-1196 Aligning filehdfs batch job defaults with hdfs sink

- changing job name to filepoll2hdfs

- changing basePath default to /xd/<jobname>

- changing suffix default to csv

XD-1196 Changing job name to filepollhdfs for consistency with other job names

XD-1196 Changing properties for HDFS output to be directory, fileName and fileExtension

XD-1196 Updating test script with new property names
XD-1187 Support for --transport for admin

The alias for --transport has been added to xd-admin.
Remove mongodb dependency from spring-xd-hadoop

- Remove org.springframework.data:spring-data-mongodb:$springDataMongoVersion
  compile dependency from spring-xd-hadoop as this is only needed by
  any module and the module can use spring-xd-extension-mongodb
- Since this removes mongodb on XD admin, launcher classpath, the Mongodb
  autoconfiguration is avoided.
XD-1177: more error checking around labels and indexed modules
XD-1207 Fix Notification Channel not correctly bound to MessageBus

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