* The WordCounter should only do one thing: count words. This makes it also easier to test.
* Add some really basic unit tests.
* Instead of only refreshing the count on enter and delete, refresh the count when the user stops typing. Also look at paste and content changes in TinyMCE.
* Use `match` instead of `replace` when it is appropriate.
* More readable code.
See #30966. Fixes#26620.
Built from https://develop.svn.wordpress.org/trunk@32856
git-svn-id: http://core.svn.wordpress.org/trunk@32827 1a063a9b-81f0-0310-95a4-ce76da25c4cd