Merge branch 'slint_port/calculator' into 'master'

.gitignore

Cargo.lock

Cargo.toml

LICENSE

LICENSE-GPL

LICENSE-MIT

README.md

calculator/.cargo/config.toml

calculator/Cargo.toml

calculator/build.rs

calculator/src/main.rs

calculator/ui/app.slint

orbutils/Cargo.lock

orbutils/Cargo.toml

orbutils/src/background/main.rs

orbutils/src/calendar/main.rs

orbutils/src/calendar/theme.css

orbutils/src/character_map/main.rs

orbutils/src/editor/main.rs

orbutils/src/file_manager/main.rs