Version 1, Update 4

• We added a new positioning to support absolutely positioned AutoLayout children
  • By default, positioning is set to 'auto', which preserves the existing behavior of layout out the child using auto layout.
• We've updated AlignItems to accept a new baseline value.

Bug fixes:

• Fixed a bug in undo/redo where multiple updates to synced state might clobber the values on the undo/redo stack.
• Removed flipVertical from our docs and types since it is not implemented.

Additionally, we updated the Plugin API with some improvements to WidgetNode. For more information see: Plugin API Version 1, Update 46.