update about "redescending" / "weakly redescending" etc


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robustbase@608 694ef91d-65df-0310-b7bb-92e67a308ead
update "links" in comments

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robustbase@609 694ef91d-65df-0310-b7bb-92e67a308ead