Fix
* Make legacy FormatManager skip uninstalled plugins ([888](https://github.com/imageio/imageio/issues/888)) ([`76a87c1`](https://github.com/imageio/imageio/commit/76a87c19d060abd12b0f9d0a35413d204fc29c74))
Other
* Remove unneeded image_mode references ([816](https://github.com/imageio/imageio/issues/816)) ([`eeafb8d`](https://github.com/imageio/imageio/commit/eeafb8d5e6b4ec351afa13a9ca05297cd7c8728a))
* Remove xcode reference (dead link) ([`d1c3e5e`](https://github.com/imageio/imageio/commit/d1c3e5e02f3b2cc2fbf5988ddc8e1c3419b87ceb))