[opensuse-factory] Providing alternative packages for bzip2 and gzip

Hi: I have been playing around with newer, multithreaded implementations of bzip2 and gzip and is my impression that we need to provide "update-alternatives" to them, so users are able to select their favorite tool. I came to the conclusion that I have no reason to use the traditional "bzip" when compared to "pbzip2" or gzip when compared to "pigz". attached is a compression and decompression time graph of all this tools to give you an idea ;) Cheers.