See https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
```
__CARGO_FIX_YOLO=1 cargo clippy --fix --all-targets --workspace --exclude gstreamer-player --exclude i-slint-backend-linuxkms --exclude uefi-demo --exclude ffmpeg -- -A clippy::all -W clippy::useless_format
cargo fmt --all
```
`__CARGO_FIX_YOLO=1` is a hack, but it does help a lot with the tedious fixes where the result is fairly clear.
The use of the rotation-* properties creates a hidden Rotate item,
which applyes a rotation to the renderer. This rotation (and translation
by rotation origin) is now also applied when the partial renderer
computes the dirty regions.
Based on API review, PlatformBuilder becomes BackendSelector with
a slightly smaller API surface but more options, such as selecting
Metal or Vulkan rendering.
Updated the version from 1.1 to 1.2
Renamed the header to "Slint Royalty-free Desktop, Mobile, and Web Applications License"
Added definition of "Mobile Application" and grant of right
Moved "Limitations" to 3rd section and "License Conditions - Attributions" to 2nd section
Added flexibility to choose between showing "MadeWithSlint" as a dialog/splash screen or on a public webpage
Moved the para on copyright notices to section under "Limitations"
This is the initial implementation based on DRM dumb buffers,
which cleans up various things at the same time:
- DRM output is separate from GBM and DRM dumb buffer displays.
The latter two re-use the former.
- The timer refresh for the Vulkan KHR Display rendering lives
now with the KHR display code, in hope to be replaced with a
better mechanism in the future.
What's missing still is support for partial updates as well as
rendering with our own software renderer.
Move this back out of render() again and make it stateful in the renderer. Reduces the amount of book-keeping required and it's always the same callback anyway.
