Version 1.7
    o Bug fix, when the input in the venn() function is a QCA solution.
    o Argument "counts" in function venn() is now used as a numerical vector for
      the set intersections (thanks to William Robbins for the suggestion)

Version 1.6
    o Major change in the treatment of custom intersections, the package
      now supports set unions (using the plus sign), as well as set intersections.
      Multiple intersections are now separated with a comma.
    o New argument "borders" to function venn(), defaulted to TRUE in order to
      preserve backwards compatibility. When deactivated, only the custom
      intersections will be plotted.

Version 1.5
    o Adaptation to package QCA version 3.0
    o Replaced the argument "nofsets" with "snames", in function getZones()
    o Argument "transparency" renamed to "opacity"
    o Arguments "zcolor" and "col" in function venn() now accept a single character
      expression, as well as a character vector to specify colors
    o Removed suggestion to package QCAGUI, which is now merged into package QCA
    o Argument cexil in function venn() is now defaulted to 0.6, with an automatic
      change to 0.5 for six sets and 0.45 for seven sets
    o When the input is a list, invisibly return the truth table and the counts for
      each intersection, with an attribute called "intersections" containing its 
      elements (thanks to Jeena Ganga for the suggestion)

Version 1.2
    o Adaptation to package QCA version 2.2 
    o Fixed a bug when interpreting a SOP expression, the negation of a set
      was interpreted as the set itself
    o When the expression is a valid R statement, quoting is not necessary
      anymore

Version 1.1
    o Fixed minor bugs
    o New feature to draw a Venn diagram using a SOP (sum of products) expression
    o QCA type objects can have transparency based on the inclusion score
    o Parameters for borders can have lengths, recycled to the length of zones
    
      The following were all suggested by Tom Wenseleers (with thanks):
      
    o The plot window is now forced to a square, using asp = 1
    o New shapes for 4 and 5 sets, to maximize the space for intersections
    o Default color styles, and associated border colors
    o Variable text size for the intersection labels and for the set names
    
    
Version 1.0
    o First version of the package

