
version 0.1 (2012-12-23):
  Initial version
version 0.2 (2013-03-05):
  Many improvements, 
version 0.4 (2014-12-03)
  Fixes so that it compiles without problems in new R versions
version 0.5 (2015-01-07)
  Makefile changes so that it compiles without problems in new R versions
