request: figaspect API change

First of all thank you for this great package.

The matshow function computes the aspect ratio of the figure with:

  in matplotlib/
  def matshow(*args,**kw):
    # Extract actual aspect ratio of array and make appropriately sized figure
    w,h = figaspect(arr)

before displaying it.
figaspect takes the array as an argument and compute its aspect ratio with:

  in matplotlib/
  def figaspect(arr):
    # Extract the aspect ratio of the array
    nr,nc = arr.shape[:2]
    arr_ratio = float(nr)/nc

Could it be changed such that figaspect takes a float as its argument and the 2
lines to compute arr_ratio are moved from figaspect to matshow before calling
figaspect ? (+ change the figaspect doc string)
It will make figaspect more general and allow us to create a figure with a given
aspect ratio without copying/pasting of nearly all the figaspect machinery.

Does anybody intend to add a Patch object to draw polygons with holes (I do not
know how to do it) ?

Thank you,