Various utilities for use with scalajs-react.

• AsyncStateFromProps, for when your state (or part of it) is derived asynchronously from your props
• FutureView, for when you want to render a Future
• Messages, a global notification/alert system, which can be used to automatically report the result of a Future (such as a user action)
• GlobalBusyIndicator, to show a global indicator (such as a spinning animation) while a Future is in progress
• SnapshotUtils: various utilities for working with StateSnapshot, including a factory similar to the simple pre-1.2.0 factory, and .toTagMod to get ^.onChange + ^.value/^.checked for free, given a StateSnapshot zoomed to the value of an input field.