include branch as analytics custom variable

src/UI/Shared/NzbDroneController.js

@@ -32,6 +32,7 @@ define(
                         piwik.setReferrerUrl('');
                         piwik.setCustomUrl('http://local' + window.location.pathname);
                         piwik.setCustomVariable(1, 'version', window.NzbDrone.Version, 'page');
+                        piwik.setCustomVariable(2, 'branch', window.NzbDrone.Branch, 'page');
                         piwik.trackPageView(title);
                     }
                     catch (e){

src/UI/index.html

@@ -76,6 +76,7 @@
         ApiRoot: 'API_ROOT',
         ApiKey : 'API_KEY',
         Version: 'APP_VERSION',
+        Branch : 'APP_BRANCH',
         Analytics: APP_ANALYTICS
     };
 </script>