Merge branch 'master' into release

ckeditor/CHANGES.md

ckeditor/LICENSE.md

ckeditor/adapters/jquery.js

ckeditor/build-config.js

ckeditor/ckeditor.js

ckeditor/contents.css

ckeditor/lang/af.js

ckeditor/lang/ar.js

ckeditor/lang/az.js

ckeditor/lang/bg.js

ckeditor/lang/bn.js

ckeditor/lang/bs.js

ckeditor/lang/ca.js

ckeditor/lang/cs.js

ckeditor/lang/cy.js

ckeditor/lang/da.js

ckeditor/lang/de-ch.js

ckeditor/lang/de.js

ckeditor/lang/el.js

ckeditor/lang/en-au.js