moved code for creating the data set abd model formula from function quadFuncEst() into a new function quadFuncModel()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/micecon@1972 95fa4d17-b1e8-0310-9d42-a43d67248e42
added predict() method for objects returned by quadFuncEst()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/micecon@1973 95fa4d17-b1e8-0310-9d42-a43d67248e42
added tests for predict() method for objects returned by quadFuncEst()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/micecon@1974 95fa4d17-b1e8-0310-9d42-a43d67248e42
added predict() method for objects returned by translogEst()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/micecon@1975 95fa4d17-b1e8-0310-9d42-a43d67248e42
added tests for predict() method for objects returned by translogEst()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/micecon@1976 95fa4d17-b1e8-0310-9d42-a43d67248e42
if predict.quadFuncEst() and predict.translogEst() are applied to panel data models, a warning message is issued

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/micecon@1977 95fa4d17-b1e8-0310-9d42-a43d67248e42
added function sfactor2bw() (currently without NAMESPACE entry, documentation, and tests)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/micecon@1978 95fa4d17-b1e8-0310-9d42-a43d67248e42