Zookeeper Inspector reports "List of default node viewers is empty" when not specifically run from the zookeeper-contrib/zookeeper-contrib-zooinspector directory

This is a follow-up to the issue ZOOKEEPER-3943 and the discussion on https://github.com/apache/zookeeper/pull/1551.  PR 1551 fixes the location issue for all of the various Icons used by the UI, but does not address a similar issue with the defaultNodeViewers.cfg and defaultConnectionSettings.cfg files (as pointed out in the PR comments).  

As a result, if one builds a "Fat JAR" of the Zookeeper Inspector application and then moves it to a different directory, this error appears when inspecting a node at runtime:

WARN [main] (ZooInspectorManagerImpl.java:851) - List of default node viewers is empty"

And the node viewer window cannot populate correctly.