subr/pkg_install{,_rpm}.subr: honour ${PKG_{PKGLIST,RPM}_DISABLE}.
    vars/build.vars:host_tools: moves mpackage from dist as mpackage_host.
    vars/build.vars:{ntctty,psxscl{,_strace},ptycon}: specify ${PKG_SRC_TARBALL_DISABLE:=1}.
    vars/build.vars:minipix: specify ${{PKGLIST,RPM}=1}.
    vars/dist_etc.vars: removed.
    vars/env.vars: adds {PKGLIST,RPM,SRC_TARBALL}_DISABLE.
    vars/invariants_tarballs.vars:pkgp_dist_tarball_src(): honour ${PKG_SRC_TARBALL_DISABLE}.
    vars/invariants_zipdist.vars: ensure build directories for packages in the pkglist.native exist.
    vars/{invariants_zipdist,mpackage_host}.vars: {reference,provide} mpackage/ symlink.