First pre-release version of v5.0.0, published to NPM with the next tag.

This release contains all the breaking changes described in the 5.0 wiki page.

• #2564 TimezonePicker performance optimization significantly reduces time to compute timezone items.

• #2585 Added new icons: globe-network, tree, snowflake

• fix TS compiler issue in IHotkeysTarget with latest @types/react@16.3

  lerna ERR! ERROR in [at-loader] ../../node_modules/@blueprintjs/core/dist/esm/components/hotkeys/hotkeysTarget.d.ts:4:18
  lerna ERR!     TS2320: Interface 'IHotkeysTarget' cannot simultaneously extend types 'Component<any, any, any>' and 'ComponentLifecycle<any, any, never>

• 📦 move react-transition-group from peer to standard dependency #2511
• 📦 new 3.0 upgrade script, improve 2.0 upgrade script #2488
• new icons: crown and tree-diagram #2507
• fix typings of HTML Table component #2509
• fix upgrade script's treatment of removed props #2486
• Button fix button width with large CSS icon only #2497
• Tabs fix vertical style #2495
• Tag improve outline behavior #2428
• Spinner adjust stroke width #2491
• Switch fix align-right style #2494
• Toaster.create() throws error if used within lifecycle method #2522
• ensureElement utility supports React.Fragment #2499

• new Example frame! #2489
  • Example component is now composed in render() instead of extend BaseExample
  • examples are clearly separated from surrounding text with structure for example/options/source
  • completely rewrite CSS examples so they're more similar to React examples, with checkboxes for each modifier
  • deprecate BaseExample; will remove in next beta release
• upgrade Documentalist, fix React key warnings #2510

• new icons: crown, shield, tree-diagram (#2519, #2448)
• Toaster.create() throws an error if ReactDOM.render() returns null (#2523)
  • React 16 has a breaking change where ReactDOM.render() returns null if invoked within a lifecycle method, which breaks the Toaster.create() contract of returning a Toaster instance
  • we handle this by throwing an error, forcing you to refactor your usage of the Toaster to either an element ref or a singleton module

• #2413 Fix EditableText CSS classes.

• ⭐️ #2325 Support for customizing the CSS class namespace pt-
  • in the upcoming 3.0 release, we will change this namespace to bp3- to avoid style conflicts with previous versions of Blueprint on the same page
  • added a new docs page about Classes to encourage use of the forward-compatible Classes constants
• ⭐️ #2341 Slider now uses percentages instead of pixels for layout, resulting in effortless resizes! (🎩 @reiv)
• 📦 #2362 Upgrade to Normalize.css 8.0.0 to fix font-family issues on some components (🎩 @reiv)
• 🔨 #2328 Fix Webpack externals so *.bundle.js files are as light as possible
• 🔨 #2367 Fix TypeScript bundling with at-loader on Windows (🎩 @reiv
• #2399 Added Overlay didClose and Popover popoverDidClose lifecycle props!
  • now possible with react-transition-group onExited method (did not exist in 1.0)
• #2131 ContextMenu now re-creates its DOM element when it closes, allowing it to be used in other overlays like Dialog
• #2344 InputGroup now supports .pt-fill modifier (🎩 @qcz)
• #1861 InputGroup now has default right padding when rightElement is omitted
• #2382 Popover improved focus event handling, particularly when switching tabs (🎩 @reiv)
• #2400 Fix Callout icon positioning
• #2377 Fix Checkbox onChange 😨 (🎩 @js-um)
• #803 Fix ContextMenu so it will remain inside the viewport
• #1188 Fix Overlay outside click logic when hasBackdrop=false
• #2401 Fix Portal onChildrenMount so it is invoked after children mount
• #2365 Fix large TagInput tag-remove button size
• #2409 File input Sass variables now have !default

• ⭐️ #2325 Support for customizing the CSS class namespace pt-
  • in the upcoming 3.0 release, we will change this namespace to bp3- to avoid style conflicts with previous versions of Blueprint on the same page
  • added a new docs page about Classes to encourage use of the forward-compatible Classes constants
• #2390 Fix hot reload support (🎩 @dan-katz)
• #2118 Fix scroll syncing when widths/heights change (🎩 @mcintyret)