Release 2.0.4

Added

• agate/ImageItem to have imageItem, caption and image publicClassnames
• agate/Popup to have a content publicClassname
• agate/TabGroup prop onSelect to handle onClick event on it

Fixed

• agate/Keypad to fire onChange event with a correct value payload
• agate/Panels/TabbedPanels to not show console error when there is no children
• agate/SwitchItem border color for Gallium skin when selected and focused
• agate/TabGroup to pass onSelect to ui/Group