Start converting gen_release to use CHPL_HOME.
fix the non-checkout code path
fix syntax
Add create_tarball script that wraps non-clone version of gen_release.
more comments
update create_release_tarball.bash script to use new non-clone setting
Correct dirnames inside tarball for non-clone version.
le sigh -- portability issues with tar
Detect bsd tar and use correct transform arg.
fix typo
Merge pull request #877 from thomasvandoren/regular-tarballs

Update gen_release to support regular automated builds.

Updates to support building tarballs more regularly (e.g. after each push to master).

Update gen_release to work inside existing repository -- the automated build system
already ensures a pristine working copy. Add new bash script in util/cron/ that calls
gen_release with non-clone settings and a version number like `1.10.0.deadbee`.

Also, update `create_release_tarball.bash` script to use new non-clone setting.