Packaging script changes, mostly from recent Shroud work.
Packaging script changes, mostly from recent Shroud work.

Use single DSTROOT for all builds.

Verify code signing/Developer ID works before attempting to package.

Upload to updatez.xml so real appcast doesn’t get overwritten before we’ve tested.

Don’t automatically increment build number after uploading.
ssp/Pester,ssp/Pester,nriley/Pester,ssp/Pester,ssp/Pester,ssp/Pester,nriley/Pester