Determine if intermediate caching of property derived configurations can be simplified or removed.

[EdColeman]

As a follow-on to single node property storage in ZooKeeper (issue https://github.com/apache/accumulo/issues/1454)

The code contains multiple levels of caching configuration derived from properties. When the single node storage is implemented, the intermediate caching may no longer be necessary and code simplification / clean-up may be possible.

Possible candidate:

• The configuration caching in ServerConfigurationFactory.
• The handling and usage of updateCount in classes that extend AccumuloConfiguration.