Keep buttons in their associated features

Contributing all buttons in one place goes against the designs that we
set out at the beginning of the project's rewrite and that multiple of
us have been following since then.

react/features/toolbox/components/web/OverflowMenuItem.js

@@ -0,0 +1,60 @@
+import PropTypes from 'prop-types';
+import React, { Component } from 'react';
+
+/**
+ * A React {@code Component} for displaying a link to interact with other
+ * features of the application.
+ *
+ * @extends Component
+ */
+class OverflowMenuItem extends Component {
+    /**
+     * {@code OverflowMenuItem} component's property types.
+     *
+     * @static
+     */
+    static propTypes = {
+        /**
+         * A succinct description of what the item does. Used by accessibility
+         * tools and torture tests.
+         */
+        accessibilityLabel: PropTypes.string,
+
+        /**
+         * The icon class to use for displaying an icon before the link text.
+         */
+        icon: PropTypes.string,
+
+        /**
+         * The callback to invoke when {@code OverflowMenuItem} is clicked.
+         */
+        onClick: PropTypes.func,
+
+        /**
+         * The text to display in the {@code OverflowMenuItem}.
+         */
+        text: PropTypes.string
+    };
+
+    /**
+     * Implements React's {@link Component#render()}.
+     *
+     * @inheritdoc
+     * @returns {ReactElement}
+     */
+    render() {
+        return (
+            <li
+                aria-label = { this.props.accessibilityLabel }
+                className = 'overflow-menu-item'
+                onClick = { this.props.onClick }>
+                <span className = 'overflow-menu-item-icon'>
+                    <i className = { this.props.icon } />
+                </span>
+                { this.props.text }
+            </li>
+        );
+    }
+}
+
+export default OverflowMenuItem;