Main difference is the logic for rebuilding a model. Should
run faster now, but has slight differences in example files.
Imported changes from ph2orch.
Plan to make phreeqcpp a subdirectory of ph2orch/src.
git-svn-id: svn://136.177.114.72/svn_GW/phreeqcpp/trunk@1601 1feff8c3-07ed-0310-ac33-dd36852eb9cd
