gb_storage: add tarball-based archive functionality
gb_storage: add tarball-based archive functionality

DrXyzzy/smc,sagemathinc/smc,tscholl2/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,tscholl2/smc,DrXyzzy/smc,sagemathinc/smc,sagemathinc/smc,tscholl2/smc,sagemathinc/smc,DrXyzzy/smc