* Multi-select mouse events now honor the event's window
This prevents errors from opening JSONEditor in a child window (such as `window.open` or third-party libraries like react-new-window).
* Add a demo of showing a JSONEditor in a child window
* Minor spelling fixes
* Further improvements to new window support
Use `event.view` instead of the global `window`. Copy VanillaPicker styles in the example so that the color picker is correctly styled.
* Add 'noopener'
This helps security; otherwise, JavaScript running in the context of the new window can access the original window object via the `window.opener` property, even if it's a different origin.
* Update modal handling for new windows
There are two approaches we could take; we could use the existing modalAnchor property and make callers responsible for setting it, or we could modify the default handling to default to the node's container body. For now, I chose to make callers responsible.
Rename showTransformModal's `anchor` parameter to `container`; as far as I can tell, `anchor` didn't work properly.