Revision 0.2-1 (2014-02-20):
* first public release of the package

Revision 0.2-0 (2014-02-18):
* print.lpmodeler()
* customizable problem type (max or min)
* documentation (using roxygen2)

Revision 0.1-2 (2013-11-24):
* update to Rsymphony 0.1-17 (time_limit, gap_limit, node_limit,
  first_feasible, verbosity, write_mps, write_lp)

Revision 0.1-1 (2013-04-25):
* speed improvement by using 'environment' instead of 'list'
* checkDims()
* update to Rsymphony 0.1-15

Revision 0.1-0 (2012-06-05):
* newProblem(), addVariable(), addConstraint(),
  setCoeff(), setPoint()
* mipSolve() with Rsymphony 0.1-14
