detect package version history

Version 0.2-2, May 2, 2012
    * inst/COPYING file removed (standard license).

Version 0.2-1, November 25, 2011
    * Help pages edited.

Version 0.2-0, October 18, 2011
    * svabu and related functions added.
    * summary: nobs was returned as NULL,
      so AIC was not printed. Now fixed.
    * R (>= 2.13.0) added to DESCRIPTION
      (reported by Uwe Ligges).

Version 0.1-0, September 27, 2011
    * First public release on CRAN.