value function signature changed:
    color: v => console.log(v.raw, v.cooked, v.node, v.result)

v.raw is previous value before any plugin
v.cooked is previous value after all plugin and validation check

• value-function: add v.raw, v.prev->v.cooked
• v.raw only exists when it have value previously, so raw in v make sense
• remove strSugar of '&'
• result.options renamed => result.config
• config.state act as initial state (fallback state)