Display 0% for progress bar and CSS tweak.

src/Radial.react.js

@@ -3,7 +3,7 @@ var React = require('react/addons');
 var Radial = React.createClass({
   render: function () {
     var percentage;
-    if (this.props.progress && !this.props.spin) {
+    if ((this.props.progress !== null && this.props.progress !== undefined) && !this.props.spin) {
       percentage = (
         <div className="percentage"></div>
       );

styles/right-panel.less

@@ -64,6 +64,7 @@
         margin-left: 16px;
         padding: 6px 10px;
         font-weight: 400;
+        display: inline-block;
         &:hover {
           border-radius: 40px;
           background-color: @color-background;
@@ -76,6 +77,7 @@
         &.disabled {
           opacity: 0.5;
           &:hover {
+            border-radius: 40px;
             background-color: transparent;
           }
         }