Add geometry parameters

[njoyard]

This adds geometry parameters to wob.

  -W <px> Define display width in pixels, defaults to 400.
  -H <px> Define display height in pixels, defaults to 50.
  -o <px> Define border offset in pixels, defaults to 4.
  -b <px> Define border size in pixels, defaults to 4.
  -p <px> Define bar padding in pixels, defaults to 4.
  -a <s>  Define anchor point; one of 'top', 'left', 'right', 'bottom', 'center' (default).
          May be specified multiple times.
  -M <px> Define anchor margin in pixels, defaults to 0.

[francma]

Thanks :slightly_smiling_face: