Minor improvements and bugfixes.

   xypolygon.R
   eval.fv.R
   fv.R
   quadrattest.R
   rmhmodel.R
   util.R
	Replaced any(duplicated(X)) by anyDuplicated(X)

   hypersub.R
      Bug fix in $<-.hyperframe: coerced strings to factors.

   NEWS
      updated