Script to build the whole release.
(cherry picked from commit e3440c62435d374fb124cfe9235ee55fb8b548d5)
Clean build files before and create release tarball after.

Clean the build files up before starting a fresh release to
avoid any pollution.

Create the release tarball after so we have a single script
to do builds with.
(cherry picked from commit 65fbda5a5b92d132e84712e07819daf7c5b011ea)