Merge remote-tracking branch 'official/master' into multiple-outputs

Conflicts:
	pkgs/development/libraries/cairo/default.nix
	pkgs/development/libraries/freetype/default.nix
	pkgs/development/libraries/glib/default.nix
	pkgs/development/libraries/libpng/default.nix
	pkgs/development/libraries/pango/default.nix
	pkgs/tools/typesetting/tex/texlive/default.nix
	pkgs/top-level/all-packages.nix