add clone generic and methods

git-svn-id: https://hedgehog.fhcrc.org/bioconductor/trunk/madman/Rpacks/oligoClasses@72806 bc3139a8-67e5-0310-9ffc-ced21a209358
update makeFeatureGRanges Rd file
merge with collab

git-svn-id: https://hedgehog.fhcrc.org/bioconductor/trunk/madman/Rpacks/oligoClasses@72901 bc3139a8-67e5-0310-9ffc-ced21a209358
Add argument empty to duplicateBLList
Add documentation for generic and method for clone