Added a function to parse the query argument string.
Dendrogram enhancements.

- Converted dendrogram to use tighter option processing

- Renamed newNodes to onNodeCreate

- Added onNodeDestroy option

- Fixed bug where reappearing nodes lose any event handlers they used to have,
  when they reappear
Simplifying geodots plugin options.
Simplified geonodelink's and mapdots' option structures.
Abstracting setOption and setOptions methods into single point of implementation.
Created tangelo widget base class; made all tangelo widgets inherit from it.

The base class is $.tangelo.widget and it provides _setOption, _setOptions, and
an empty _update method.  The option methods are designed to recognize the
_notAccessors property in the child widget and dispatch either the creation of
an accessor or a direct setting of the attribute.
Merge branch 'query-arg'
Merge branch 'plugin-option-defaults'