sstephenson/ruby-build — pull request #326 by quark-zju (2013-03-12 08:54:38+00:00)
Title: Keep downloaded tarball sometimes

In slow Internet environment, downloading a source tarball takes a lot of time.
Do not delete the tarball if `tar xf` fails or user uses `-k/--keep` to keep the source.
Additionally, use `--continue` option of `curl` and `wget` to resume download if previous download is interrupted.