Fixes issues with rotating videos.

By default image rotation does not automatically modify the aspect ratio settings of rotated output, however this patch fixes that. If an aspect ratio is not already set and a rotation means that the aspect ratio is not the same as the current ratio then a new ratio will be applied.

This patch also provides automated functionality where if the aspect ratio does not match the width and height, the ratio corrected width and height and height are returned instead of the actual width and height. This will mean that any output processed from a mis matching file will be as expected.

Relates to issue #22.

Marked as beta as it may have unintended consequences that could result in errors.