gif 0.11.1

GIF de- and encoder
Documentation
# v0.11.1

- Frames out-of-bounds of the screen descriptor are again accepted by default.
- Added `DecodeOptions::check_frame_consistency` to turn this validation on.

# v0.11

- Rename `Reader` to `Decoder`.
- Reworked `Decoder` into `DecodeOptions`.
- The decoding error is now opaque and no longer allocates a string. Adding
  more information or more error conditions is forward compatible.
- Replace the lzw decoder with `weezl`, up to +350% throughput.
- The dysfunctional C-API has been (temporarily?) removed
  - It may get reintroduced as a separate crate at some point
- Added a `std` feature. It must be active for now.