Merge branch 'master' into deploy.spirit

* master:
  Makefile: Add a new thing for running arbitrary commands.
  Makefile: Change the tag for maintenance to be `MAINT'.
  Makefile: Fix `squote' to have the right number of `\'s.
  bin/chroot-maint: Run `ldconfig' after an update.
  bin/chroot-maint: Fix mistakenly indented file-contents literals.