[frio] Cleanup CSS/UI

- Fix panel usage
- Remove double submit button in theme config
- Remove textarea phantom label when not provided
- Improve filebrowser button display
- Fix slider input display
- Simplify user menu styles

view/theme/frio/templates/field_textarea.tpl

@@ -1,6 +1,7 @@
-
 	<div class="form-group field textarea">
+	{{if $field.1}}
 		<label for="id_{{$field.0}}">{{$field.1}}</label>
+	{{/if}}
 		<textarea class="form-control text-autosize" name="{{$field.0}}" id="id_{{$field.0}}" {{if $field.4}}{{$field.4 nofilter}}{{/if}} aria-describedby="{{$field.0}}_tip">{{$field.2}}</textarea>
 	{{if $field.3}}
 		<span class="help-block" id="{{$field.0}}_tip" role="tooltip">{{$field.3 nofilter}}</span>