mc() direct, no S3 generic+default method

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robustbase@596 694ef91d-65df-0310-b7bb-92e67a308ead
get rid of many goto`s -- (is this code tested enough??)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robustbase@597 694ef91d-65df-0310-b7bb-92e67a308ead
more testing

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robustbase@598 694ef91d-65df-0310-b7bb-92e67a308ead