bin/make_dist_tarball.sh

bin/make_dist_tarball.sh

This includes all submodules *except* ceph-object-corpus and
ceph-erasure-code-corpus.

This is a bit different that autotools' version:

 - compiled man pages
 - some autotools cruft
 - src/.git_version
 - compiled *.in files
 + .git*
 + CMake stuff
 + copyright files
 + readme files
 + cmake/
 + debian/
 + doc/
 + keys/
 + qa/
 + systemd/
 + tons of other stuff we should probably have included

All in all, I think it's much more complete.

Signed-off-by: Sage Weil <sage@redhat.com>