jbf> TableDataSetConsumer should be renamed ZAxisDataSetComsumer or something like that
 DataSet.hasZAxis()?

jbf> Suggested Properties for DataSets:
  spacecraft         Spacecraft enumeration object
  xRange             DataRange object suggestion
  yRange             DataRange object suggestion
  defaultRenderer    Renderer Object
  xOffset            offsets to be applied to yscan
  mouseModules       list of mouseModules that should be installed

jbf> suggested logic for per-plane properties for das2Stream client-side DataSets:
  the data of the primary plane is merged with the stream and packet properties.
  name clashes to be resolved by using plane overrides packet overrides stream.
  
jbf> suggest introduce getPropertyNames() method and policy that rebinners 
  propogate the properties listed.  Alternatively, this could be expressed as
  an optional property.

eew> Agreed proeprties for DataSets
    xTagWidth        Datum the extent of relevance of the x tags
    yTagWidth        Datum "   "   "  of the y tags
       introduce Units.percent, which is useful for specifying log width.
  rebinner           Rebinner Object
  cacheTag           Description of the start, end and resolution satisfied by this
                     data set.
  plane-list			 java.util.List 

eew> Agreed plane identifiers
	 peaks - peaks
	 weights - rebinning weights (always dimensionless)
	 uncertainty - errors plane


Vector
   get(i)->Datum
   getDouble(i,Units)->double
   getUnits()->Units

Table
   get(i,j)->Datum
   getDouble(i,j,Units)->double
   length(index)->int
   getUnits()->Units

HyperTable    // arbitrary rank
   rank()->int
   get(i,j,k,l)->Datum
   getDouble(i,j,k,l,Units)->double
   length(index)->int
   getUnits()->Units
   slice(index,idim)->HyperTable
   collapse(offset,length,idim)->HyperTable

TableDataSet
   tableCount()->int
   getData(i)->Table
   getDepend(index)->String[]
   getTags(String,i)->Vector
   getPlane(name)->DataSet

VectorDataSet
   getData->Vector
   getDepend()->String[]
   getTags(String)->Vector
   getPlane(name)->DataSet

HyperTableDataSet
   slice or collapse to reduce to TableDataSet

