add spinny_wheel.

  you background something and then you run spinny_wheel and it makes a simple
  ascii spinner (\, -, /, |, loop) until jobs -eq 0.

  sorry, doesn't work in dash(1) b/c dash seems to have the behaviour whereby
  'jobs' emits nothing if the output is a pipe, and i am not gonna be creating
  tempfiles for this.

  inspiration -- network install with a physical console terminal which has slow
  screen-update-ness and someone is mandating rsync be run with '-v' so
  They Know It Is Working.  spinny_wheel saves a lot of display i/o.