Updated all dialogs to define their primary button, I've selected the one that had been specified for focus, but the primary button isn't dependent on focus, it's a UX feature

src/components/views/dialogs/ErrorDialog.js

@@ -59,7 +59,7 @@ module.exports = React.createClass({
                     {this.props.description}
                 </div>
                 <div className="mx_Dialog_buttons">
-                    <button onClick={this.props.onFinished} autoFocus={this.props.focus}>
+                    <button className="mx_Dialog_primary" onClick={this.props.onFinished} autoFocus={this.props.focus}>
                         {this.props.button}
                     </button>
                 </div>