BUG Fix broken installer assets and session crash

src/Dev/Install/Installer.php

@@ -3,7 +3,9 @@
 namespace SilverStripe\Dev\Install;
 
 use Exception;
+use SilverStripe\Control\Cookie;
 use SilverStripe\Control\HTTPRequest;
+use SilverStripe\Control\HTTPRequestBuilder;
 use SilverStripe\Control\Session;
 use SilverStripe\Core\CoreKernel;
 use SilverStripe\Control\HTTPApplication;
@@ -199,10 +201,8 @@ PHP
             }
         }
 
-        // Mock request
+        // Build request
-        $session = new Session(isset($_SESSION) ? $_SESSION : array());
+        $request = HTTPRequestBuilder::createFromEnvironment();
-        $request = new HTTPRequest('GET', '/');
-        $request->setSession($session);
 
         // Install kernel (fix to dev)
         $kernel = new CoreKernel(BASE_PATH);
@@ -211,6 +211,9 @@ PHP
 
         // Build db within HTTPApplication
         $app->execute($request, function (HTTPRequest $request) use ($config) {
+            // Suppress cookie errors on install
+            Cookie::config()->set('report_errors', false);
+
             // Start session and execute
             $request->getSession()->init($request);
 

src/Dev/Install/config-form.html

@@ -273,7 +273,7 @@
 
 									<span id="saving_top" style="display: none">
 										&nbsp;
-										<img src="<?=FRAMEWORK_NAME; ?>/images/network-save.gif" alt="Saving">
+										<img src="<?=FRAMEWORK_NAME; ?>/src/Dev/Install/client/images/network-save.gif" alt="Saving">
 										(this will take a minute or so)
 									</span>
 								</p>