Fix bug in get_id_count.
Fix bug in model="replace" or projection="replace".

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rgl@1048 79a1b648-8b68-254f-b20b-c0b50f5137bf
Fix initial viewpoint

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/rgl@1049 79a1b648-8b68-254f-b20b-c0b50f5137bf