JCBC-170: Update documentation on test classes.

This changeset updates the JUnit tests and adds docblocks
for clarity.

Change-Id: I127eafcd02b58d37d019b5a2275c63223d55591d
Reviewed-on: http://review.couchbase.org/23021
Reviewed-by: Deepti Dawar <deepti.dawar@globallogic.com>
Tested-by: Deepti Dawar <deepti.dawar@globallogic.com>
Reviewed-by: Michael Nitschinger <michael.nitschinger@couchbase.com>