0.3.1-alpha2

• ComboBox / ComboboxItem widget
• Slider widget
• Popup widget
• Overlay layer
• Service registry for states
• Settings service (serialize / deserialize data)
• Direct access of states in callbacks
• Impl RawWindowHandle for Context (wip)
• Sent requests to window shell
• Layout fixes and stack layout example
• Many web fixes
• State cleanup method
• Refactor setting of styling selectors
• TextBox select all (Ctrl + a)
• Text input support for !, @, #
• Borderless window