Fix up timeout, improve contrast on "show more", add responsive style

for extremely wide monitors

app/assets/javascripts/components/features/ui/components/columns_area.jsx

@@ -3,12 +3,15 @@ import PureRenderMixin from 'react-addons-pure-render-mixin';
 const style = {
   display: 'flex',
   flex: '1 1 auto',
-  justifyContent: 'flex-start',
   overflowX: 'auto'
 };
 
 const ColumnsArea = React.createClass({
 
+  propTypes: {
+    children: React.PropTypes.node
+  },
+
   mixins: [PureRenderMixin],
 
   render () {