I have a request for future versions of roundcube. Can you make the distribution files untar into a directory with the version name in it. I think it would be beneficial to most people to be able to do this:
cd /var/www/your/document/root tar zxvf roundcube_webmail_version#.tar.gz
and have it untar to the directory 'roundcubemail_version#' instead of just untarring to 'roundcubemail'. That way it can be untarred in the same parent directory without having to move the old directory out of the way or clobbering old files.