Added code to flush on build

Replaced unnecessary references to ?flush=1 and ?flush=all.
Added code to enable the build task to also flush.

_config/config.yml

@@ -7,4 +7,7 @@ LeftAndMain:
     - 'betternavigator/javascript/BN.LeftAndMain.Preview.js'
 ContentController:
   extensions:
-    - BetterNavigator
+    - BetterNavigator
+DevelopmentAdmin:
+  extensions:
+    - FlushOnDevBuild

code/FlushOnDevBuild.php

@@ -0,0 +1,14 @@
+<?php
+
+/**
+ * via swaiba https://groups.google.com/d/msg/silverstripe-dev/RNWCiFAnRI0/bABhA5Otnl4J
+ */
+
+class FlushOnDevBuild extends Extension {
+	function beforeCallActionHandler($request,$action){
+		if(!$this->owner->response->isFinished() && $action=='build' && $request->getVar('flush')){
+			SS_TemplateLoader::instance()->getManifest()->regenerate(true);
+			SSViewer::flush_template_cache();
+		}
+	}
+}

templates/BetterNavigator.ss

@@ -53,8 +53,8 @@
 						<a href="$Link?isDev=1"><span class="bn-icon-devmode"></span>Dev Mode</a>
 					<% end_if %>
 					
-					<a href="$Link?flush=all"><span class="bn-icon-flush"></span>Flush Templates</a>
+					<a href="$Link?flush"><span class="bn-icon-flush"></span>Flush</a>
-					<a href="/dev/build/?flush=1" target="_blank"><span class="bn-icon-db"></span>Build Database</a>
+					<a href="/dev/build/" target="_blank"><span class="bn-icon-db"></span>Build &amp Flush</a>
 					<a href="/dev/" target="_blank"><span class="bn-icon-tools"></span>Dev Menu</a>
 					
 				</div>