Cleanup

Dependencies

• [2] WQ2VQ7H3 Use hydra-module.nix in the tests
• [3] LZVO64YG Merge in the first bits of the API work
• [4] UGA45FNC Add a plugin for backing up builds in s3
• [5] A3A2O37I Work around 9P corruption on 32-bit
• [6] WGDX4QRI Adjust to the NixOS/Nixpkgs merge
• [7] IZYR3KTL release.nix: Get rid of the "system" argument
• [*] T4LLYESZ * Nix expression for building Hydra.

Change contents

• replacement in release.nix at line 177
  [3.324]→[2.534:613](∅→∅)
  − machine = hydraServer (builtins.getAttr system build); # build.${system}
  [3.324]

  [3.537]
  + machine = hydraServer build.${system};
• replacement in release.nix at line 192
  [3.211]→[2.882:961](∅→∅)
  − machine = hydraServer (builtins.getAttr system build); # build.${system}
  [3.211]

  [3.513]
  + machine = hydraServer build.${system};
• replacement in release.nix at line 221
  [3.209]→[3.162:232](∅→∅),[3.162]→[3.162:232](∅→∅)
  − let hydra = builtins.getAttr system build; in # build."${system}"
  [3.209]

  [3.232]
  + let hydra = build.${system}