Switches tarball format over to .xz compression; closes #4979.
Switches tarball format over to .xz compression; closes #4979.
damianmoore/shotwell,ritchiewilson/shotwell,polymeris/shotwell,abrauchli/shotwell,abrauchli/shotwell,Sanva/shotwell-gsoc,polymeris/shotwell,h4ck3rm1k3/shotwell,ritchiewilson/shotwell,jimbonator/shotwell,Sanva/shotwell-gsoc,ritchiewilson/shotwell,damianmoore/shotwell,abrauchli/shotwell,h4ck3rm1k3/shotwell,damianmoore/shotwell,jimbonator/shotwell,jimbonator/shotwell,polymeris/shotwell,h4ck3rm1k3/shotwell,Sanva/shotwell-gsoc