Release 0.22.2
- Undeprecate `unsafe` trait accessors. Further evaluation showed that their
deprecation should be delayed until trait `impl` specialization is available.
- Fixed magic bytes used to detect `tiff` images.
- Added `DynamicImage::from_decoder`.
- Fixed a bug in the `PNGReader` that caused an infinite loop.
- Added `ColorType::{bits_per_pixel, num_components}`.
- Added `ImageFormat::from_path`, same format deduction as the `open` method.
- Fixed a panic in the gif decoder.
- Aligned background color handling of `gif` to web browser implementations.
- Fixed handling of partial frames in animated `gif`.
- Removed unused direct `lzw` dependency, an indirect dependency in `tiff`.