/cc @mhdawson

We removed the macOS setup docs in b804f76 but I don't believe we're fully automated for release machines so we need to retain this documentation somewhere but it also needs updating because this seems to change with each new macOS version (specifically the signing cert stuff) and whenever I do it my notes from previous attempts never seem to fully get me over the line. So it might be good to have someone go through the steps and document it themselves.

This is in the doc that we deleted in the above commit:

• For release machines:
  • Install PackageMaker, download "Auxiliary Tools for Xcode - Late July 2012" from the Apple Developer site to get it, put it in ~iojs/PackageMaker.app (RV: need to check whether Node 6 needs this any more, possibly that died with Node 4?)
  • Install Packages from http://s.sudre.free.fr/Software/Packages/about.html
  • Install xz utilities from http://macpkg.sourceforge.net/
  • Install Node.js Foundation code signing and package signing certificates
    • Available from either the secrets repository under "release" as a passwordless .p12 file
    • OS X 10.10: In Keychain Access, "Import Items" and add both the Installer and Application certificates to the "System" (not "login" which is default)
    • OS X 10.10: Find the private key for Node.js Foundation under System in Keychain Access, "Get Info" for it, switch to "Access Control" and allow access by all applications. This step requires a physical keyboard under El Capitan and onward.
    • Command line alternative (all OS X?): sudo security import /path/to/id.p12 -k /Library/Keychains/System.keychain -T /usr/bin/codesign -T /usr/bin/productsign
  • Add ssh_config as ~iojs/.ssh/config
  • Install the staging key as ~/.ssh/id_rsa