[gzip.c] use --fast for bzip2, added lzma format
[gzip.c] use --fast for bzip2, added lzma format

mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs