Fix bug identified by CRAN:  you couldn't remove a viewpoint

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rgl@1128 79a1b648-8b68-254f-b20b-c0b50f5137bf
Speed up the examples and demo, at request of CRAN

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rgl@1129 79a1b648-8b68-254f-b20b-c0b50f5137bf
Update news and version

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rgl@1130 79a1b648-8b68-254f-b20b-c0b50f5137bf