TypeError in save_image with autoconvert=True on Python 3.2

The error rised was:

	unsupported operand type(s) for +: 'dict_items' and 'dict_items'

In Python 3 `dict.items()` returns an iterator, not a list. One iterator can not be added to another iterator.
Instead of getting items of both dict we can update the dict returned from `prepare_image` with `options` and then to `options` to be equal to updated kwargs.

 This will work on Python3 and Python2.