added functionality for plotting STFDF rasters from krigeST e.g.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/plotkml@476 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
updated html for plotKML function

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/plotkml@477 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Brian Ripley tested plotKML on Mac and got some error messages with kml_open.R

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/plotkml@478 edb9625f-4e0d-4859-8d74-9fd3b1da38cb