This package provides two mechanisms for storing preferences and one
mechanism for storing user interface state within a JMRI profile:
Complex preferences within an XML element provided by the object storing
and retrieving the element.
Simple preferences within a Preferences
Complex user interface state within an XML element provided by the object
storing and retrieving the element.
These three classes provide arbitrary read/write access to the
underlying storage, such that writing a users preferences does not require
any part of a JMRI application have knowledge of every object that manages