use xyplot2 instead of xyplot
merge collab

* collab:
  use xyplot2 instead of xyplot

 xyplot

# Please enter a commit message to explain why this merge is necessary,
# especially if it merges an updated upstream into a topic branch.
#
# Lines starting with '#' will be ignored, and an empty message aborts
# the commit.

git-svn-id: https://hedgehog.fhcrc.org/bioconductor/trunk/madman/Rpacks/VanillaICE@72944 bc3139a8-67e5-0310-9ffc-ced21a209358