emacs: Deprecate "guix-init.el".

'guix-init' served 2 purposes:

- to autoload guix commands (by requiring 'guix-autoloads');
- and to autoload Emacs packages installed with Guix (by requiring
  'guix-emacs').

The second purpose is not actual anymore, as Emacs package handles this
task now, so there is no need in 'guix-init' anymore.

* emacs/guix-init.el: Do not require 'guix-emacs'.  Add a deprecation
  message.
* doc/emacs.texi (Emacs Initial Setup): Recommend to use
  'guix-autoloads' instead of 'guix-init'.

system: Do not create "site-start.el".

After commits 004ea62 and 092dd65, Emacs can find packages in a system
profile, so it autoloads guix code without additional hacks, which can
be removed now.

* gnu/system.scm (emacs-site-file, emacs-site-directory): Remove.
(operating-system-etc-service): Adjust accordingly.
(operating-system-environment-variables): Remove EMACSLOADPATH.

gnu: Remove "r-repository" property.

* gnu/packages/bioinformatics.scm (r-biocgenerics, r-s4vectors,
r-iranges, r-genomeinfodb, r-xvector, r-genomicranges)[properties]:
Remove "r-repository" property.

gnu: pari-gp: Syntactic changes.

* gnu/packages/algebra.scm (pari-gp)[arguments]: Use modify-phases syntax.

services: xorg: Fix ~/.xsession handling.

Fixes a regression introduced in c510cbb4ecb270ca3edf282c6769aa2bfb144822.

* gnu/services/xorg.scm (xinitrc)[builder]: Add missing 'apply' when
XSESSION-FILE exists.

gnu: modem-manager: Update to 1.4.14.

* gnu/packages/freedesktop.scm (modem-manager): Update to 1.4.14.

gnu: webkitgtk: Update to 2.12.0.

* gnu/packages/webkit.scm (webkitgtk): Update to 2.12.0.

gnu: shepherd: Update to 0.3.1.

* gnu/packages/admin.scm (shepherd): Update to 0.3.1.

guix build: '--with-source' correctly matches versioned file names.

* guix/scripts/build.scm: Use the right 'package-name->name+version'
procedure.  Fixes a regression introduced in
1b846da8c372bee78851439fd9e72b2499115e5a.
* tests/scripts-build.scm ("options->transformation, with-source, with
version"): New test.

gnu: libressl: Update to 2.3.3.

* gnu/packages/tls.scm (libressl): Update to 2.3.3.

Signed-off-by: Leo Famulari <leo@famulari.name>

emacs: Use space to separate package name and version in heading.

Reported by Ludovic Courtès <ludo@gnu.org>.

* emacs/guix-ui-package.el (guix-package-name): Check 'spec' property.
(guix-package-info-insert-heading): Use "name version" for button label,
write name specification to 'spec' property.

emacs: Fix converting scheme into elisp expression.

* emacs/guix-geiser.el (guix-geiser-eval-read): Replace #f/#t with nil/t
  only when they follow "(" or " ".

gnu: Add AIDE.

* gnu/packages/admin.scm (aide): New variable.

gnu: icecast: Update to 2.4.3 [fixes CVE-2015-3026].

* gnu/packages/xiph.scm (icecast): Update to 2.4.3.

services: postgresql: Use syslog.

Fixes <http://bugs.gnu.org/23064>.
Reported by Danny Milosavljevic <dannym@scratchpost.org>.

* gnu/services/databases.scm (%default-postgres-config): Add
'log_destination' line.
(postgresql-shepherd-service): Add requirement on 'syslogd'.

doc: Add "lightweight desktop" OS config example.

* gnu/system/examples/desktop.tmpl (packages): Remove XFCE and
RATPOISON.
(services): Add 'gnome-desktop-service' and 'xfce-desktop-service'.
* gnu/system/examples/lightweight-desktop.tmpl: New file.
* Makefile.am (EXAMPLES): Add it.
* doc.am (OS_CONFIG_EXAMPLES_TEXI): Add
doc/os-config-lightweight-desktop.texi.
* gnu/system/install.scm (/etc/configuration-files)[directory]: Add
lightweight-desktop.tmpl.

derivations: Raise an error when a module file is not found.

Suggested by Jookia.

* guix/derivations.scm (&file-search-error): New error condition.
(search-path*): Raise it when 'search-path' returns #f.
* guix/gexp.scm (search-path*): Remove.
* guix/ui.scm (call-with-error-handling): Add case for
'file-search-error?'.
* tests/derivations.scm ("build-expression->derivation and invalid
module name"): New test.

derivations: Add 'module->source-file-name'.

* guix/derivations.scm (module->source-file-name): New procedure.
(%imported-modules): Use it.
* guix/gexp.scm (imported-modules): Likewise.

substitute: Gracefully handle TLS errors.

* guix/scripts/substitute.scm (with-networking): Use 'match-lambda*' and
add case for 'gnutls-error'.

import: cran: Accept single URL in addition to single URL.

* guix/import/cran.scm (package->upstream-name): Match single URL in
  addition to list of URLs.