First version released on CRAN: 0.5 (2007-11-29): First Release
Second version released on CRAN: 0.7.1 (2009-03-13): New Functions added
Third version released on CRAN: 0.7.2 (2009-04-24): Small bugs fixed 
Fourth version released on CRAN: 0.8.1 (2009-05-07): Major bug fixed in code and in algorithm
