Merge branch 'core-updates'

build-aux/hydra/gnu-system.scm

configure.ac

doc/guix.texi

gnu-system.am

gnu/packages/acl.scm

gnu/packages/admin.scm

gnu/packages/audio.scm

gnu/packages/avahi.scm

gnu/packages/base.scm

gnu/packages/bash.scm

gnu/packages/bioinformatics.scm

gnu/packages/bootstrap.scm

gnu/packages/certs.scm

gnu/packages/check.scm

gnu/packages/cmake.scm

gnu/packages/code.scm

gnu/packages/commencement.scm

gnu/packages/compression.scm

gnu/packages/cups.scm

gnu/packages/curl.scm