preview doesn't work in windows

[aachrisg]

Hi. Enjoying the package.

I noticed the preview doesn't work in windows. The reason is related to running 'dot' with the output to stdout, and loading stdout as a png. But in windows the buffer contents file will be invalid and so not displayed as an image - its possibly because of line endings.

I hacked it to output to a tmp file by using -O when running "dot" and then manually loaded the temp file in emacs.