* Remove useless CSS declaration
* Remove commented out styles
* Merge duplicate declarations
* Remove even more commented out code
* Move footer mq to footer declaration
* Remove more useless code
* Stop vendor prefixing for IE below 11
* Remove useless vendor prefixing
* Merge identical declarations
* Fix 1px overflow in content wrapper
* Fix explorer scrolling when open on mobile
* Remove unused import
* Add Redux performance measurements to explorer menu
* Rewrite explorer reducer to avoid unnecessary operations
* Stop changing reducer state on every action regardless of type
* Remove redundant children.isFetching property in nodes reducer
* Remove redundant children.isLoaded property in nodes reducer
* Remove redundant children.isError property in nodes reducer
* Refactor nodes explorer reducer with sub-reducer
* Fix linting issue
* Remove unused class name
* Change default icon className from empty string to null
* Remove old TODO comment
* Hoist icons in ExplorerItem component for better performance
* Add comment
* Add tooling for performance measurement of React components
* Clean up explorer panel component definition
* Make performance measurements opt-in
* Improve alignment of page explorer menu on mobile
* Close explorer on touchend rather than touchstart
* Comment out performance measurement code
* Remove fade transition completely
* Update to the latest jest version
* Update react dependencies
* Migrate React.PropTypes to PropTypes package
* Add prop-types to the package.json
* Update transition-group import to its new package
* Update jest snapshots
* Exclude node_modules from webpack babel-loader
Move webpack configuration to a subfolder in the client directory
Remove trailing whitespace
Rename prd.config.js to prod.config.js
Simplify lint:js target path
This is where developers expect it to be, similar to Django and other
projects. The version info still exists at the old `wagtail.wagtailcore`
location, for backwards compatibility.
Fixes #2557
