Changes in version 1-0.3 (09/15/2015)
    * fixed empty LHS problem in grouped plot (reported by Andrew Collier)
    * Updated for arules version 1-2.0

Changes in version 1-0.2 (6/29/2015)
    * fixed imports from non-base standard packages.
    * plot (graph) now honors font family set via par(). 
      (Bug reported by May Yang) 
    * igraph: Updated NAMESPACE since igraph introduced functions with 
      names that clash with arules and seriation. 
      Transitioned to igraphs new layout mechanism. 
    * itemsets: scatterplot is now also defaut for itemsets.

Changes in version 1-0.0 (12/07/2014)
    * Improved LHS annotation for grouped plot

Changes in version 0-1.9 (3/10/2014)
    * Cleaned up dependencies on Rgraphviz

Changes in version 0.1-8 (2/18/2014)
    * Cleaned up dependencies (moved most to imports)

Changes in version 0.1-7 (8/11/2013)
    * plot checks now if 0 rules/itemsets are used
    * scatterplots with a single rule now display correctly
    * transition from igraph0 to igraph

Changes in version 0.1-6 (5/25/2013)
    * plot method matrix does not accept custom colors 

Changes in version 0.1-5 (3/02/2012)
    * fixed namespace (imports seriation now)

Changes in version 0.1-4 (11/7/2011)
    * fixed font family for igraph under windows (is now Arial).

Initial version 0.1-0 (12/17/2010)
