gnu: Add python-requests-mock.

* gnu/packages/openstack.scm (python-requests-mock,
  python2-requests-mock): New variables.

gnu: Add python-webob.

* gnu/packages/python.scm (python-webob, python2-webob): New variables.

gnu: Add python-oslo.context.

* gnu/packages/openstack.scm (python-oslo.context,
  python2-oslo.context): New variables.

gnu: Add python-oslo.serialization.

* gnu/packages/openstack.scm (python-oslo.serialization,
  python2-oslo.serialization): New variables.

gnu: sfarklib: Update to 2.24.

* gnu/packages/compression.scm (sfarklib): Update to 2.24.

gnu: Add ruby-log4r.

* gnu/packages/ruby.scm (ruby-log4r): New variable.

gnu: Add r-dbi.

* gnu/packages/statistics.scm (r-dbi): New variable.

nls: Add "TRANSLATORS:" comment about Texinfo.

* gnu/packages/abiword.scm: Add comment above 'description'.

doc: Add guidelines for synopses and descriptions.

* doc/guix.texi (Synopses and Descriptions): New node.
* doc/contributing.texi (Submitting Patches): Add item that
  cross-references it.

doc: Change authorship to "The GNU Guix Developers".

* doc/guix.texi: Replace outdated @author list with just "The GNU Guix
  Developers".

gnu: Add r-lazyeval.

* gnu/packages/statistics.scm (r-lazyeval): New variable.

gnu: Add r-assertthat.

* gnu/packages/statistics.scm (r-assertthat): New variable.

gnu: Add ruby-gherkin3.

* gnu/packages/ruby.scm (ruby-gherkin3): New variable.

lint: Add 'check-texinfo-markup' checker.

* guix/script/lint.scm (check-description-style): Check for invalid
  Texinfo markup.
* tests/lint.scm: Test it.

emacs: Add "View build log" action to build popup.

* emacs/guix-command.el (guix-run-view-build-log): New function.
  (guix-command-additional-execute-arguments,
  guix-command-special-executors): Add entries for "View build log"
  action.
* emacs/guix-utils.el (guix-find-file-or-url): New function.

emacs: Add modes for viewing build logs.

* emacs/guix-build-log.el: New file.
* emacs.am (ELFILES): Add it.
* doc/emacs.texi (Emacs Build Log): Document it.  New node.
  (Emacs Interface): Add it.
* doc/guix.texi (Top): Likewise.

emacs: Display guix command errors in the minibuffer.

* emacs/guix-main.scm (output+error): New procedure.
  (guix-command-output): Use it.
* emacs/guix-base.el (guix-command-output): Display error output in the
  minibuffer.

emacs: Add customization groups for faces.

* emacs/guix.el (guix-faces): New custom group.
* emacs/guix-base.el (guix-operation-option-key): Use it.
  (guix-define-buffer-type): Generate faces group.
* emacs/guix-info.el: Adjust faces to use new groups.
  (guix-info-faces): New custom group.
* emacs/guix-list.el: Likewise
  (guix-list-faces): New custom group.

guix: lint: Check for meaningful origin file names.

* guix/scripts/lint.scm (check-source-file-name): New procedure.
  (%checkers): Add 'source-file-name' checker.
* tests/lint.scm ("source-file-name", "source-file-name: v prefix")
  ("source-file-name: valid", "source-file-name: bad checkout")
  ("source-file-name: good checkout"): New tests.
* doc/guix.texi (Invoking guix lint): Mention file name check.

guix: packages: Add origin-actual-file-name.

* guix/scripts/graph.scm (uri->file-name, node-full-name): Move origin file
  name logic to...
* guix/packages.scm (origin-actual-file-name): ...here.
* tests/packages.scm ("origin-actual-file-name")
  ("origin-actual-file-name, file-name"): New tests.