gnu: newsbeuter: Deprecate in favour of newsboat.

* gnu/packages/syndication.scm (newsbeuter): Redefine using
‘deprecated-package’.
* gnu/packages/patches/newsbeuter-CVE-2017-12904.patch: Delete file.
* gnu/packages/patches/newsbeuter-CVE-2017-14500.patch: Likewise.
* gnu/local.mk (dist_patch_DATA): Remove both.

derivations: Fix typo in docstring.

* guix/derivations.scm (derivation-prerequisites): Fix typo in docstring.

ssh: Pass an empty "exceptfds" set to 'select'.

Previously the redirect code could end up exiting prematurely because of
an uninteresting "exceptional condition" on the socket (info "(libc)
Waiting for I/O").

* guix/ssh.scm (remote-daemon-channel): Pass the empty list as the third
argument to 'select'.  It was a mistake to pass a non-empty list there
in the first place.

doc: Fix typo in 'guix environment' example.

* doc/guix.texi (Invoking guix environment): Add missing @ in example.

store: Fix potential over-reads in 'import-paths'.

Previously 'process-stderr' would always pass a bytevector of MAX-LEN to
then daemon in the %stderr-read case (i.e., 'import-paths'), instead of
LEN (where LEN <= MAX-LEN).

In practice the extra bytes didn't cause a protocol violation or
anything because they happen at the end of the stream, which typically
contains the canonical sexp of the signature, and the extra zeros were
just ignored.

* guix/serialization.scm (write-bytevector): Add optional 'l' parameter
and honor it.
* guix/store.scm (process-stderr): Pass LEN to 'write-bytevector'.

ssh: Work around 'get-bytevector-some' bug.

This works around <https://bugs.gnu.org/30066> and noticeably improves
performance when using GUIX_DAEMON_SOCKET=ssh://HOST (the redirect code
was transferring data to guix-daemon one byte at a time!).

* guix/ssh.scm (remote-daemon-channel)[redirect]: Define 'read!' and use
it instead of 'get-bytevector-some'.

gnu: rrdtool: Update to 1.7.0.

* gnu/packages/rrdtool.scm (rrdtool): Update to 1.7.0.
[native-inputs]: Add bc, perl, and tzdata.
[arguments]: Remove obsolete substitution in ‘pre-configure’ phase.
Set TZDIR for tests in new ‘prepare-test-environment’ phase.
Add ‘remove-native-input-references’ phase for example scripts.

gnu: fio: Update to 3.3.

* gnu/packages/benchmark.scm (fio): Update to 3.3.

gnu: perl-list-moreutils: Update to 0.428.

* gnu/packages/perl.scm (perl-list-moreutils): Update to 0.428.

gnu: libmtp: Update to 1.1.14.

* gnu/packages/libusb.scm (libmtp): Update to 1.1.14.

gnu: python-idna: Update to 2.6.

* gnu/packages/python.scm (python-idna): Update to 2.6.

gnu: ocaml-zed: Update to 1.6.

* gnu/packages/ocaml.scm (ocaml-zed): Update to 1.6.

gnu: rrdtool: Re-order imports.

* gnu/packages/rrdtool.scm: Order imports alphabetically.

gnu: rrdtool: Use HTTPS for home page.

* gnu/packages/rrdtool.scm (rrdtool)[home-page]: Use HTTPS.

gnu: wine: Remove duplicate supported-systems field.

* gnu/packages/wine.scm (wine)[supported-systems]: Remove duplicate
field.

gnu: linux-libre: Update to 4.14.13.

* gnu/packages/linux.scm (%linux-libre-version): Update to 4.14.13.
(%linux-libre-hash): Update hash.

gnu: linux-libre@4.9: Update to 4.9.76.

* gnu/packages/linux.scm (linux-libre-4.9): Update to 4.9.76.

gnu: linux-libre@4.4: Update to 4.4.111.

* gnu/packages/linux.scm (linux-libre-4.4): Update to 4.4.111.

gnu: grub-hybrid: Don't try to install files that already exist.

* gnu/packages/bootloaders.scm (grub-hybrid)[arguments]: Check if a file
already exists in the destination directory before installing it.

gnu: wine: Limit supported architectures to ones that can build our wine.

* gnu/packages/wine.scm (wine)[supported systems]: New field, limit to
architectures which can build for their selected '#:system'.