nix-prefetch-* scripts are in hydra svn now

Dependencies

• [2] RJ5EREYU hydra: add bazaar to path
• [3] M3A5PZIH hydra: Clarify the dependency on BDW-GC.
• [4] FGI75W53 move nix-prefetch-* into tarball
• [5] UHMUHQMU hydra: fix tarball build, add pre suffix to tarballs
• [6] QK2OXCKP hydra/release.nix: move manual to tarball build, restore version in store path for tarball build
• [7] FV2M6MOT hydra: use autoconf/-make
• [*] T4LLYESZ * Nix expression for building Hydra.

Change contents

• edit in release.nix at line 24
  [3.188]→[3.0:248](∅→∅),[3.248]→[2.0:83](∅→∅)
  −

  − cp ${"${nixpkgs}/pkgs/build-support/fetchsvn/nix-prefetch-svn"} src/script

  − cp ${"${nixpkgs}/pkgs/build-support/fetchgit/nix-prefetch-git"} src/script

  − cp ${"${nixpkgs}/pkgs/build-support/fetchhg/nix-prefetch-hg"} src/script

  − cp ${"${nixpkgs}/pkgs/build-support/fetchbzr/nix-prefetch-bzr"} src/script