Resolve the case of the missing tmp and other mysteries in the release script

It looks like the release script got a bit discombobulated in the move to gobble (which is pretty slick, by the way). I believe this will resolve the issues in #1189 and #1181.

I have only been able to verify that the build directory ends up with the right stuff to just before the first commit (tested with `exit 1` on line 31) is made in release.sh, since I wanted to make absolutely sure I didn't do anything accidentally.