Fix "IE doesn't keep you logged in between restarts (or page reloads)"...

Fix "IE doesn't keep you logged in between restarts (or page reloads)" problems by disabling cookie check in iframe.  issue #2218 & issue #2183

resources/static/communication_iframe/start.js

@@ -16,6 +16,15 @@
 
   network.init();
 
+  // Do not check to see if cookies are supported in the iframe.  Just
+  // optimistically try to work by running network requests.  There are
+  // cases (especially in IE) where our checks will fail but our actual
+  // requests will not.  issue #2183
+  // (NOTE: if we want to try to improve failure modes for users with
+  //  a "disable 3rd party cookies"-like preference set in their browser,
+  //  we may need to re-visit this)
+  network.cookiesEnabledOverride = true;
+
   var chan = Channel.build({
     window: window.parent,
     origin: "*",