v9.0.11

This release has a rewritten tilecache which, combined with some libvips improvements, should be dramatically faster. Flicker on updates should also be fixed. The image window has much better next / prev / refresh behaviour, a better focus indicator, and better handling of display control settings. Plus a lot of small bugfixes.

There's a Linux build on flathub, a macOS build in homebrew, and a Windows binary below.