changes file for 9969

changes/ticket9969

+  o Minor features (directory client):
+    - When downloading server- or microdescriptors from a directory server,
+      we no longer launch multiple simultaneous requests to the same server.
+      This reduces load on the directory servers, especially when directory
+      guards are in use.  Closes ticket 9969.
+    - When downloading server- or microdescriptors over a tunneled
+      connection, do not limit the length of our request to what the Squid
+      proxy is willing to handle.  Part of ticket 9969.