[DOC beta] Fix a Typo in ArrayController
Merge pull request #4295 from jherdman/fix-typo-in-array-controller

Fix a Typo in ArrayController
[DOC beta] Document HTML5 attributes available.

This adds documentation to the `attributeBindings` recently added to the
`{{input}}`, `{{textarea}}`, and `{{checkbox}}` helpers.
Add 1.4.0-beta.5 to CHANGELOG.md.
Merge pull request #4296 from rjackson/doc-html5-attributes

[DOC beta] Document HTML5 attributes available.