An exception when attempting to save an svg as <type>

The save action by default save's the image in it's current format type. That doesn't work for svg obviously. So we need to use an alternative type for it like png.

Traceback (most recent call last):
  File "/home/nadia/projects/phatch/phatch/core/api.py", line 311, in apply_action
    photo = action.apply(photo, setting, cache)
  File "/home/nadia/projects/phatch/phatch/actions/save.py", line 157, in apply
    **options)
  File "/home/nadia/projects/phatch/phatch/core/pil.py", line 647, in save
    image.save(filename, **options)
  File "/usr/lib/python2.5/site-packages/PIL/Image.py", line 1390, in save
    raise KeyError(ext) # unknown extension
KeyError: u'.svg'