Recursively process images in nested directories #64
Description
There are going to be cases where one would like to process images in nested
directories.
Currently, handing a directory into the `Thumbnails.of(File...)` method will
cause an exception to be thrown when trying to process a directory, but there
may be a use case where one would like to process the contents of the directory.
This can lead to some complications with how to output the files, as described
in the comments for Issue 63.
Original issue reported on code.google.com by coobird...@gmail.com on 21 Dec 2013 at 3:36