Merge branch 'master' into staging

* master: (23 commits)
  silver-searcher: patch bash completions location
  shairplay: init at 2016-01-01
  ocamlPackages.rope: 0.5 -> 0.6
  ocamlPackages.ocaml_gettext: 0.8.7 -> 0.8.8
  mupdf: Patch openjpeg version
  nextcloud-client: fix build after qt updates
  gstreamer.gst-plugins-bad: Patch openjpeg version
  silver-searcher: move bash completion to etc/bash-completion.d/
  neomutt: use mime.types from dedicated mime-types derivation
  mime_types: rename to mime-types
  XMLLibXML: 2.0129 -> 2.0132 fixes failing tests & CVE-2017-10672
  nixos/matrix-synapse: remove unused log_file config
  nixos: run parted with --script option (3rd)
  nixos: run parted with --script option (2nd)
  nixos/release: add nixos/tests/switch-test.nix to tested job
  nixos/system: make switch-to-configuration script pure.
  nixos/release: include mutableUsers test to release tests.
  nixos/tests: Add a test for config.users.mutableUsers.
  corebird: 1.7.2 -> 1.7.3
  nixos/matrix-synapse: make home directory configurable
  ...