Light editing to changes entries for 0.4.7.5-alpha

changes/ticket40312

   o Major bugfixes (relay, DNS):
     - Lower the DNS timeout from 3 attempts at 5 seconds each to 2 attempts at
       1 seconds each. Two new consensus parameters were added to control these
-      values. See ticket for more details on why. Fixes bug 40312; bugfix on
+      values. This change should improve observed performance under DNS load;
+      see ticket for more details. Fixes bug 40312; bugfix on
       0.3.5.1-alpha.

changes/ticket40560

   o Minor bugfixes (relay, overload):
-    - Use a fraction and assessment period of ntor handshake drops for the
-      overload general signal. Before that, a single drop could trigger an
-      overload state which was far from useful. Fixes bug 40560; bugfix on
-      0.4.7.1-alpha.
+    - Decide whether to signal overload based on a fraction and
+      assessment period of ntor handshake drops. Previously, a single
+      drop could trigger an overload state, which caused many false
+      positives. Fixes bug 40560; bugfix on 0.4.7.1-alpha.

changes/ticket40576

   o Minor bugfixes (onion service congestion control):
-    - Avoid a non fatal assert in case we can't setup congestion control on the
-      rendezvous circuit after opening. Fixes bug 40576; bugfix on
-      0.4.7.4-alpha.
-
+    - Avoid a non-fatal assertion failure in the case where we fail to set up
+      congestion control on a rendezvous circuit. This could happen naturally
+      if a cache entry expired at an unexpected time. Fixes bug 40576; bugfix
+      on 0.4.7.4-alpha.

changes/ticket40579

   o Minor bugfixes (onion service, client):
-    - Fix a fatal assert due to a guard subsystem recursion triggered by the
+    - Fix a rare but fatal assertion failure due to a guard subsystem
+      recursion triggered by the
       onion service client. Fixes bug 40579; bugfix on 0.3.5.1-alpha.