Merge pull request #227 from oakmound/fix/bump-x-image

mod: bump golang.org/x/image to v0.21.0

Merge pull request #214 from oakmound/feature/entities-with-explicit-…

…children

Feature/entities with explicit children

Merge pull request #209 from oakmound/fix/emptyfontoptions

render/font: Enforce default truetype font height for Height()

Merge pull request #208 from oakmound/fix/unbindcaller-resetcount

event/internal: Unbind calls now take the current reset of the bus

Merge pull request #207 from oakmound/release/v4.0.0

Release/v4.0.0

Merge pull request #204 from oakmound/feature/v4-docs-and-tests

Doc + refactor pass 1 for oak v4

Merge pull request #196 from oakmound/feature/v4-events

event: overhaul api

Update COMPATIBILITY.md

Merge pull request #188 from oakmound/feature/android

Add experimental android support

Merge pull request #182 from oakmound/feature/arm-test-runner

Add Linux/ARM64 support and automated tests for it