the parent runs before the child, it closes some pipe file
  descriptors which causes the child to fail due to a bad file
  descriptor.  So we just use the normal open() function instead.
  
  This fixes NIX-14 (intermittent nix-pull failures).

* Removed some dead code (successor stuff) from nix-push.
* Updated terminology in the tests (store expr -> drv path).
* Check that the deriver is set properly in the tests.

* Use force flag in `mv' to prevent silly interactive questions (this
  happens with shared Nix stores).

  invariant by registering references through the manifest.
* Added a test for nix-pull.

* Use the new patch downloader.

* Accept the NarHash line.
* Clear substitutes in `nix-channel --update'.

* Add /nix/var/nix/manifests directory.

  substitute mechanism) creates a store path by downloading full NAR
  archives and/or patches specified in the available manifests.

  Any combination of present paths, full downloads, and patches can be
  used to construct the target path.  In particular, patches can be
  chained in sequence; and full NAR archives of the target path can be
  omitted (i.e., patch-only deployment is possible).  A shortest path
  algorithm is used to find the smallest set of files to be downloaded
  (the edge weights are currently file sizes, but one can imagine
  taking the network speed to the various source into account).

  Patches are binary deltas between two store paths.  To be precise,
  they are the output of the `bsdiff' program applied to the NAR
  archives obtained by dumping (`nix-store --dump') the two store
  paths.  The advantage of diff'ing NAR archives (and not, say, doing
  file-by-file diffs) is that file renames/moves are handled
  automatically.  The disadvantage is that we cannot optimise creation
  of unchanged files (by hard-linking).

* Made the dependencies on bzip2 and the shell explicit.

* Use curl instead of wget.

  --register-[substitutes|successors].

$ nix-instantiate --help
error: unknown flag `--help`
Try `nix-instantiate --help' for more information.

:-)

  "i686-linux" instead of "i686-suse-linux").

  The script nix-install-package takes a `Nix package file' (which
  contains one or more derivations, along with URLs of Nix caches),
  unpacks it, pulls the caches, and installs the derivations in the
  user's environment.

  For best results, associate the command `xterm -e
  /nix/bin/nix-install-package' with the MIME type
  `application/x-nix-package' and visit
  http://losser.st-lab.cs.uu.nl/~eelco/test/.

* Fixed a segfault caused by the buffering of stderr.
* Fix now allows the specification of the full output path.  This
  should be used with great care, since it by-passes the normal hash
  generation.
* Incremented the version number to 0.4 (prerelease).

  store, and print its hash.

  the same time.

  substituting for (obvious, really).

* For greater efficiency, nix-pull/unnar will place the output in a
  path that is probably the same as what is actually needed, thus
  preventing a path copy.

* Even if a output id is given in a Fix package expression, ensure
  that the resulting Nix derive expression has a different id.  This
  is because Nix expressions that are semantically equivalent (i.e.,
  build the same result) might be different w.r.t. efficiency or
  divergence.  It is absolutely vital for the substitute mechanism
  that such expressions are not used interchangeably.

  etc. correctly.
* Fixed nix-switch.