gnu: Add emacs-ebuild-mode.

* gnu/packages/emacs.scm (emacs-ebuild-mode): New variable.

Signed-off-by: Alex Kost <alezost@gmail.com>

gnu: Add emacs-lua-mode.

* gnu/packages/emacs.scm (emacs-lua-mode): New variable.

Signed-off-by: Alex Kost <alezost@gmail.com>

gnu: Add r-bsgenome-mmusculus-ucsc-mm10.

* gnu/packages/bioinformatics.scm (r-bsgenome-mmusculus-ucsc-mm10): New
  variable.

guix: Add downloader for Mercurial repositories.

* guix/build/hg.scm: New file.
* guix/hg-download.scm: New file.
* Makefile.am (MODULES): Add them.

gnu: openssl: Fix CVE-2016-2177 and CVE-2016-2178.

* gnu/packages/patches/openssl-CVE-2016-2177.patch,
gnu/packages/patches/openssl-CVE-2016-2178.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/tls.scm (openssl/fixed): Use them.

gnu: Add python-wcwidth and python2-wcwidth.

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

Co-authored-by: Leo Famulari <leo@famulari.name>

gnu: Add log4cpp.

* gnu/packages/logging.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.

gnu: Add gengetopt.

* gnu/packages/popt.scm (gengetopt): New variable.

gnu: Add teensy-loader-cli.

* gnu/packages/flashing-tools.scm (teensy-loader-cli): New variable.
* gnu/packages/patches/teensy-loader-cli-help.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

store: Add #:select? parameter to 'add-to-store'.

* guix/store.scm (write-arg): Remove 'file' case.
(true): New procedure.
(add-to-store): Add #:select? parameter and honor it.  Use hand-coded
stub instead of 'operation'.
(interned-file): Add #:select? parameter and honor it.
* doc/guix.texi (The Store Monad): Adjust 'interned-file' documentation
accordingly.

gnu: grue-hunter: Move to (gnu packages games).

* gnu/packages/grue-hunter.scm: Remove.  Move contents to...
* gnu/packages/games.scm (grue-hunter): ... here.  New variable.
* gnu/local.mk (GNU_SYSTEM_MODULES): Adjust accordingly.

packages: The 'source' can be any lowerable object.

* guix/packages.scm (expand-input): Use 'struct?' instead of 'origin?'
when matching SOURCE.
(package-source-derivation): Use 'lower-object' instead of
'origin->derivation'.
* tests/packages.scm ("package-source-derivation, local-file"): New
test.
* doc/guix.texi (package Reference): Update 'source' documentation
accordingly.

packages: 'origin->derivation' expects an origin and nothing else.

* guix/packages.scm (origin->derivation): Rename 'source' parameter to
'origin'.  Move cases where SOURCE is a string to...
(package-source-derivation): ... here.

packages: Recognize the '.Z' extension.

Reported by thomasd on #guix.

* guix/packages.scm (patch-and-repack)[decompression-type]: Add "Z".

gnu: pumpa: Build with qtbase.

* gnu/packages/pumpio.scm (pumpa)[inputs]: Remove qt, add qtbase.

gnu: pinentry-qt: Build with qtbase.

* gnu/packages/gnupg.scm (pinentry-qt)[inputs]: Remove qt, add qtbase.

gnu: Add qttools.

* gnu/packages/qt.scm (qttools): New variable.

gnu: Add qtlocation.

* gnu/packages/qt.scm (qtlocation): New variable.

gnu: Add qtwebchannel.

* gnu/packages/qt.scm (qtwebchannel): New variable.

gnu: Add qtserialport.

* gnu/packages/qt.scm (qtserialport): New variable.