0.4.0

• Add a new ColorTheme constructor ::new like the other main types in the crate.
• Avoid reloading the scheme when changing the ColorTheme.
• Rename ThemeType::Aqua to ThemeType::AquaClassic.
• Add a fluent scheme.
• Add an Aqua scheme which mimics modern Aqua.
• Add a colors module with Html colors and Aqua dark and light precached system colors.
• Add a colors::aqua::sys module with system colors that's queried on MacOS systems (only works on MacOS).