Fetching() a url ending in .png freezes the program in certain cases
Can be seen by calling fetch() on this page https://commons.wikimedia.org/wiki/File:Picotron_screenshot_v1.png
The page itself displays a regular html page with an embedded image

Thanks @CannonTheWildWulf -- this is fixed for 0.2.0e, which falls back to fetching as a string if either the png header is missing (as in this case), or the file is corrupt (e.g. a half-downloaded png)