guix package: Introduce <manifest> and <manifest-entry> types.

* guix/scripts/package.scm (<manifest>, <manifest-entry>): New record
  types.
  (make-manifest, read-manifest, manifest->sexp, sexp->manifest,
  read-manifest, write-manifest, remove-manifest-entry, manifest-remove,
  manifest-installed?): New procedures.
  (profile-derivation): Take a manifest as the second parameter.  Use
  'manifest->sexp'.  Expect <manifest-entry> objects instead of
  "tuples".  Adjust callers accordingly.
  (search-path-environment-variables): Changes 'packages' parameter to
  'entries'.  Rename 'package-in-manifest->package' to
  'manifest-entry->package'; expect <manifest-entry> objects.
  (display-search-paths): Rename 'packages' to 'entries'.
  (options->installable): Change 'installed' to 'manifest'.  Have
  'canonicalize-deps' return name/path tuples instead of raw packages.
  Rename 'package->tuple' to 'package->manifest-entry'.  Use
  <manifest-entry> objects instead of tuples.
  (guix-package)[process-actions]: Likewise.  Rename 'packages' to
  'entries'.
  [process-query]: Use 'manifest-entries' instead of
  'manifest-packages'.

guix package: Better separate option processing.

* guix/scripts/package.scm (find-package): Rename to...
  (specification->package+output): ... this.  Rename 'name' parmameter
  to 'spec'.  Return a package and output name instead of a tuple.
  (options->installable): New procedure
  (guix-package)[process-actions]: Use it, and remove corresponding
  code.

gnu: Add gstreamer-0.10.

* gnu/packages/gstreamer.scm (gstreamer-0.10): New variable.
* gnu/packages/patches/gstreamer-0.10-bison3.patch,
  gnu/packages/patches/gstreamer-0.10-silly-test.patch: New files.
* gnu-system.am (dist_patch_DATA): Add patches.

gnu: mit-krb5: Update to 1.11.3.

* gnu/packages/mit-krb5.scm (mit-krb5): Update to 1.11.3.

guix package: Declutter the entry point.

* guix/scripts/package.scm (newest-available-packages,
  find-best-packages-by-name, find-package, upgradeable?): New
  procedures, moved from...
  (guix-package): ... here.

Change indentation rule for 'package' for the common case.

* .dir-locals.el: Change the indentation rule for 'package' to do the right
  thing for packages without an inherit clause.

list-runtime-roots: List files referenced by environment variables.

Inspired by <https://github.com/NixOS/nix/compare/772b70952f75...4ddd077bfa9a>.

* nix/scripts/list-runtime-roots.in (%store-directory): New variable.
  (proc-environ-roots): New procedure.
  (<top-level>): Use it.

doc: Augment the "Porting" section.

Reported by Andreas Enge <andreas@enge.fr>.

* doc/guix.texi (Porting): Document needed changes to (gnu packages
  bootstrap) and (gnu packages linux).

gnu: Add python2-empy.

* gnu/packages/python.scm (python2-empy): New variable.

build-system/{cmake,perl}: Don't use (guix build gnu-build-system).

Previously references to '%standard-phases' in builder-side code would
refer to the wrong one.

* guix/build-system/cmake.scm (cmake-build): Remove (guix build
  gnu-build-system) from the default MODULES value.
* guix/build-system/perl.scm (perl-build): Likewise.

gnu: gcc-4.8: Upgrade to 4.8.2.

* gnu/packages/gcc.scm (gcc-4.8): Upgrade to 4.8.2.

gnu: mesa: Update URI.

* gnu/packages/xorg.scm (mesa): Update URI.

gnu: lzip: Update to 1.15.

* gnu/packages/compression.scm (lzip): Update to 1.15.

gnu: Add libmikmod.

* gnu/packages/sdl.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

Signed-off-by: Andreas Enge <andreas@enge.fr>

gnu: Add Pem.

 * gnu/packages/pem.scm: New file.
 * gnu-system.am (GNU_SYSTEM_MODULES): Add it.

Signed-off-by: Andreas Enge <andreas@enge.fr>

gnu: Add sharutils.

* gnu/packages/compression.scm (sharutils): New variable.

gnu: rsync: Update to 3.1.0.

* gnu/packages/rsync.scm (rsync): Update to 3.1.0.

gnu: qt: Correct source uri.

* gnu/packages/qt.scm (qt-4): Correct source uri (reported by
    Cyril Roelandt <tipecaml@gmail.com>).

gnu: Add GLPK.

* gnu/packages/maths.scm (glpk): New variable.

gnu: Add GNU Alive.

* gnu/packages/system.scm (alive): New variable.