gnu: Add wicd.

Based on preliminary work by Pierre-Antoine Rault <par@rigelk.eu>

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

gnu: wpa-supplicant: Add dbus support; add wpa-supplicant-light.

* gnu/packages/admin.scm (wpa-supplicant-light): New variable containing the
  previous dbus-free package, but renamed.  Remove outdated TODO comments.
  (wpa-supplicant): Now inherits from wpa-supplicant-light but adds dbus
  support.
* gnu/system/install.scm (installation-os): Use wpa-supplicant-light.

gnu: nss-mdns: Allow the daemon's socket to be found.

* gnu/packages/avahi.scm (nss-mdns)[arguments]: New field.

services: nscd-service: Add #:name-services parameter.

* gnu/services/base.scm (nscd-service): Add #:name-services parameter.
  In 'start' field, set LD_LIBRARY_PATH based on #:name-services.
* doc/guix.texi (Base Services): Document it.
  (Name Service Switch): Link to 'nscd-service'.

system: Add bindings to configure libc's NSS.

* gnu/system/nss.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.
* gnu.scm (%public-modules): Add it.
* gnu/system.scm (<operating-system>)[name-service-switch]: New field.
  (etc-directory): Add #:nss parameter and honor it.
  (operating-system-etc-directory): Adjust call accordingly.
* doc/guix.texi (operating-system Reference): Document
  'name-service-switch'.
  (Name Service Switch): New section.

gnu: wpa-supplicant: Install man pages.

* gnu/packages/admin.scm (wpa-supplicant)[arguments]: Add
  'install-man-pages' phase.

gnu: wpa-supplicant: Use GnuTLS instead of OpenSSL.

* gnu/packages/admin.scm (wpa-supplicant)[arguments] <configure phase>:
  Set CONFIG_TLS.
  [inputs]: Add GNUTLS and LIBGCRYPT.

build: Make 'chroot' a hard requirement.

* config-daemon.ac: Error out when $ac_cv_func_chroot is not "yes".
* nix/nix-daemon/guix-daemon.cc (options): Remove #ifdef HAVE_CHROOT.
  (main): Likewise.

gnu: libffcall: Correct license field.

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

* gnu/packages/libffcall.scm (libffcall): Change license to gpl2+.

gnu: Add libffcall.

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

Co-Authored-By: Joshua S. Grant <jgrant@parenthetical.io>

Add support for 'cvs-fetch' method in origins.

* guix/cvs-download.scm, guix/build/cvs.scm: New files.
* Makefile.am (MODULES): Add them.

gnu: Add python2-dbus.

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

gnu: Add python-dbus.

* gnu/packages/python.scm (python-dbus): Add it. Makes use of dbus,
  dbus-glib and glib itself.

Remove outdated comment from svn-fetch.

* guix/svn-download.scm (svn-fetch): Remove outdated comment.

gnu: python-urwid: Remove Fedora mirror from source URI list.

* gnu/packages/python.scm (python-urwid)[source]: Remove Fedora mirror.

gnu: wpa-supplicant: Update to 2.3.

* gnu/packages/admin.scm (wpa-supplicant): Update to 2.3.  Update URLs.

guix: environment: Consider all package outputs.

* guix/scripts/environment.scm (for-each-search-path): Iterate over all
  derivation output paths.
  (packages->transitive-inputs): Process inputs that specify an output, too.

services: xorg: Add sawfish session.

* gnu/services/xorg.scm (%sawfish-session-type): New variable.
* doc/guix.texi (X Window): Mention it.

gnu: Add sawfish.

* gnu/packages/sawfish.scm (sawfish): New variable.

gnu: Add rep-gtk.

* gnu/packages/sawfish.scm (rep-gtk): New variable.