* fold Stack into Editor
* switch Change objects to be tied to editors, not values
* introduce controller
* add the "commands" concept
* convert history into commands on `value.data`
* add the ability to not normalize on editor creation/setting
* convert schema to a mutable constructor
* add editor.command method
* convert plugin handlers to receive `next`
* switch commands to use the onCommand middleware
* add queries support, convert schema to queries
* split out browser plugin
* remove noop util
* fixes
* fixes
* start fixing tests, refactor hyperscript to be more literal
* fix slate-html-serializer tests
* fix schema tests with hyperscript
* fix text model tests with hyperscript
* fix more tests
* get all tests passing
* fix lint
* undo decorations example update
* update examples
* small changes to the api to make it nicer
* update docs
* update commands/queries plugin logic
* change normalizeNode and validateNode to be middleware
* fix decoration removal
* rename commands tests
* add useful errors to existing APIs
* update changelogs
* cleanup
* fixes
* update docs
* add editor docs
#### Is this adding or improving a _feature_ or fixing a _bug_?
Debt.
#### What's the new behavior?
This removes almost all existing deprecations from previous API changes, to save on filesize and reduce complexity in the codebase going forward.
It also changes from using the `slate-dev-logger` to using the Facebook-inspired `slate-dev-warning` which can be compiled out of production builds with [`babel-plugin-dev-expression`](https://github.com/4Catalyzer/babel-plugin-dev-expression) to save even further on file size.
The only deprecations it keeps are in the `fromJSON` methods for data model changes like `.kind` and `.leaves` which may still may not have been migrated in databases, since this is a bigger pain point.
#### Have you checked that...?
* [x] The new code matches the existing patterns and styles.
* [x] The tests pass with `yarn test`.
* [x] The linter passes with `yarn lint`. (Fix errors with `yarn prettier`.)
* [x] The relevant examples still work. (Run examples with `yarn watch`.)
#### Does this fix any issues or need any specific reviewers?
Fixes: #1922Fixes: #2105Fixes: #646Fixes: #2109Fixes: #2107Fixes: #2018
* Add Prettier, with basic config and ESLint integration
* Apply Prettier to all files using `yarn lint --fix`
* Tell Prettier to ignore an empty text in a test output.
* Run Prettier on JS files not handled by ESLint, and lint them too
* rename state to value in slate core, as deprecation
* rename all references to state to value in slate core
* migrate slate-base64-serializer
* migrate slate-html-serializer
* migrate slate-hyperscript
* migrate slate-plain-serializer
* migrate slate-prop-types
* migrate slate-simulator
* fix change.setState compat
* deprecate references to state in slate-react
* remove all references to state in slate-react
* remove `value` and `schema` from props to all components
* fix default renderPlaceholder
* fix tests
* update examples
* update walkthroughs
* update guides
* update reference
* remove data from event handler signatures
* standardize known transfer types
* add setEventTransfer to docs
* update examples, fix drag/drop
* fix tests and draggable attribute setting
* Allow React 16 in peerDeps and use it for dev
* Make tests pass with React 16
Changes are cosmetic:
- React 16 no longer adds a trailing `;` to `style` attributes
- React 16 outputs `0` and not `0px` for sizes in `style`
* Reshape void component structure.
Get rid of offscreen spacer.
* Polish Embeds example `Video` component.
* Fix oversight.
* Force spacer width to be 0.
* Update tests
