big rework of error handling on requests

- central point for checking for 'error: "out of date"' response from server
- in 'out of date' state, an error dialog is shown and no further requests are sent to the server
- request queue has central point for request adding - now request count is accurate, not just for COMM requests
- request error count is cleared after a period of no requests failing

code/chat.js

@@ -132,8 +132,6 @@ window.chat.requestFaction = function(getOlderMsgs, isRetry) {
       ? function() { window.chat._requestFactionRunning = false; }
       : function() { window.chat.requestFaction(getOlderMsgs, true) }
   );
-
-  requests.add(r);
 }
 
 
@@ -183,8 +181,6 @@ window.chat.requestPublic = function(getOlderMsgs, isRetry) {
       ? function() { window.chat._requestPublicRunning = false; }
       : function() { window.chat.requestPublic(getOlderMsgs, true) }
   );
-
-  requests.add(r);
 }
 
 window.chat._public = {data:{}, oldestTimestamp:-1, newestTimestamp:-1};