Codesign all files in one step

[danielcompton]

It takes a 80-90 seconds to sign all of the files in our barebones Electron app. Looking at the debug logs, it appears as if this is because each file is getting signed individually.

Looking at the docs for codesign, it allows accepting multiple files. I think that signing many files at once could give a dramatic speedup to code signing. The files are already topologically ordered for signing, so they could probably be passed in their existing sort order.

It looks like there may be perFileOptions which would complicate things though.

Just a thought, perhaps this has already been considered.