Release of v5.1.1-alpha1

Move all banners to GitHub. Adds library phpspreadsheet to JCB. Adds import item example to demo component. Updates the Superpower class with the GetRemote class in the plugin. Ensures the super power autoloader triggers the correct repositories.

libraries/phpspreadsheet/vendor/maennchen/zipstream-php/guides/Varnish.rst

@@ -0,0 +1,22 @@
+Usage with Varnish
+=============
+
+Serving a big zip with varnish in between can cause random stream close.
+This can be solved by adding attached code to the vcl file.
+
+To avoid the problem, add the following to your varnish config file:
+
+.. code-block::
+    sub vcl_recv {
+        # Varnish can’t intercept the discussion anymore
+        # helps for streaming big zips
+        if (req.url ~ "\.(tar|gz|zip|7z|exe)$") {
+            return (pipe);
+        }
+    }
+    # Varnish can’t intercept the discussion anymore
+    # helps for streaming big zips
+    sub vcl_pipe {
+        set bereq.http.connection = "close";
+        return (pipe);
+    }