This adds a auto-orient option, which is enabled by default. I believe, most users expect their images to be rotated according to EXIF. The photo I've added to the fixtures was token by myself, I release it to the public domain.

Make sure that we close opened files after we're done with them.

Abstract out the file geometry parser within Thumbnail. This makes it possible to have different cropping and scaling controls, as the papermill gem does.

Closes #515

option to convert.

There's a case when you really don't want to make a thumbnail of only the first frame, such as making thumbnail for GIF image. This patch will check that the source and output format is an animated format, and not calling `[0]` on it.

Closes #454

styles encapsulated, to delay calling of procs until context is useful and to allow per-style processor lists

(cherry picked from commit 6a0ff6f0f76a92a25c9cbbc315d3d7d11d1d7720)