[added] formControlFeedback prop to Glyphicon

Less typing when passing a `Glyphicon` as
feedbackIcon into an `Input`.

Author: André Ligné

src/Glyphicon.js

@@ -7,19 +7,22 @@ const Glyphicon = React.createClass({
   mixins: [BootstrapMixin],
 
   propTypes: {
-    glyph: React.PropTypes.oneOf(styleMaps.GLYPHS).isRequired
+    glyph: React.PropTypes.oneOf(styleMaps.GLYPHS).isRequired,
+    formControlFeedback: React.PropTypes.bool
   },
 
   getDefaultProps() {
     return {
-      bsClass: 'glyphicon'
+      bsClass: 'glyphicon',
+      formControlFeedback: false
     };
   },
 
   render() {
     let classes = this.getBsClassSet();
 
     classes['glyphicon-' + this.props.glyph] = true;
+    classes['form-control-feedback'] = this.props.formControlFeedback;
 
     return (
       <span {...this.props} className={classNames(this.props.className, classes)}>

test/GlyphiconSpec.js

@@ -10,4 +10,22 @@ describe('Glyphicon', function () {
     assert.ok(React.findDOMNode(instance).className.match(/\bglyphicon\b/));
     assert.ok(React.findDOMNode(instance).className.match(/\bglyphicon-star\b/));
   });
+
+  it('renders without the .form-control-feedback class', function () {
+      let instance = ReactTestUtils.renderIntoDocument(
+        <Glyphicon glyph='star' />
+      );
+
+      assert.notOk(React.findDOMNode(instance).className.match(/\bform-control-feedback\b/));
+  });
+
+  context('when setting the formControlFeedback prop', function () {
+    it('should have the .form-control-feedback class set', function () {
+      let instance = ReactTestUtils.renderIntoDocument(
+        <Glyphicon formControlFeedback glyph='star' />
+      );
+
+      assert.ok(React.findDOMNode(instance).className.match(/\bform-control-feedback\b/));
+    });
+  });
 });