XD-374 Add command to list taps

* Add several utility classes for rendering textual contents to the console (E.g. text tables). Migrated from Cloud Foundry Maven Plugin / Hadoop Samples project.
* Align rendering of the Spring XD Shell banner with the Spring Rest Shell
* Add several missing package-info.java files

XD-374 Code review + add tests
XD-388 Add webhdfs dependencies to classpath

Add jar files needed to use webhdfs for hdfs sink