selection() now passes further arguments (...) to heckit2fit() so that, e.g. the "inst" argument of heckit() is not lost (so that IV estimation works again)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/sampleselection@1471 d36ae590-6c38-44c5-9ba5-7217e93607d8
minor improvement in an example

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/sampleselection@1472 d36ae590-6c38-44c5-9ba5-7217e93607d8
the "maxLik" package (on which the sampleSelection package depends on) is now imported in the NAMESPACE file so that the sampleSelection package can be used even if it is not attached but loaded

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/sampleselection@1473 d36ae590-6c38-44c5-9ba5-7217e93607d8
updated output files of R scripts (only start-up messages have changed)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/sampleselection@1474 d36ae590-6c38-44c5-9ba5-7217e93607d8
the "mvtnorm", "maxLik" and "abind" packages (on which the sampleSelection package depends on) are now imported in the NAMESPACE file so that the sampleSelection package can be used even if it is not attached but loaded

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/sampleselection@1475 d36ae590-6c38-44c5-9ba5-7217e93607d8