Create tarballs rather than gzipping naked binaries during release.
Create tarballs rather than gzipping naked binaries during release.

This has several advantages:
* The executable bit is set by default, so no need to `chmod +x` after
  decompressing.
* No need to rename binary to `stack` after decompressing.
* Can use tarball as the source argument for Docker `ADD` commands,
  for conveniently installing a stack binary into a docker image when
  the package manager not appropriate / not available.

harendra-kumar/stack,meiersi-11ce/stack,athanclark/stack,Andrew-the-Ubergeek/stack,MaxGabriel/stack,lukexi/stack,MichielDerhaeg/stack,kairuku/stack,mrkkrp/stack,Fuuzetsu/stack,phadej/stack,sinelaw/stack,supermario/stack,Heather/stack,vigoo/stack,rubik/stack,luigy/stack,bollu/stack,lukexi/stack,MaxGabriel/stack,mathhun/stack,rekka/stack,robstewart57/stack,vigoo/stack,achernyak/stack,AndrewRademacher/stack,athanclark/stack,Blaisorblade/stack,tedkornish/stack,supermario/stack,AndreasPK/stack,Andrew-the-Ubergeek/stack,AndrewRademacher/stack,adinapoli/stack,mrkkrp/stack,harendra-kumar/stack,luigy/stack,keent/stack,deech/stack,juhp/stack,MichielDerhaeg/stack,bixuanzju/stack,rrnewton/stack,adinapoli/stack,anton-dessiatov/stack,martin-kolinek/stack,rubik/stack,meiersi-11ce/stack,phadej/stack,keent/stack,fizruk/stack,sinelaw/stack,wolftune/stack,Fuuzetsu/stack,rrnewton/stack,sjakobi/stack,tedkornish/stack,rekka/stack,cabrera/stack,narrative/stack,Blaisorblade/stack,narrative/stack,bollu/stack,martin-kolinek/stack,rvion/stack,achernyak/stack,cabrera/stack,bixuanzju/stack,Heather/stack,akhileshs/stack,mathhun/stack,kairuku/stack,fizruk/stack,deech/stack,sjakobi/stack,juhp/stack,anton-dessiatov/stack,AndreasPK/stack,rvion/stack,robstewart57/stack,akhileshs/stack,wolftune/stack