First attempt at 2.5 release notes.

RELEASE-NOTES

@@ -1,3 +1,19 @@
+# Release 2.5
+ * All electrum windows are now part of the same process.  When starting
+   a new GUI electrum instance, that instance starts a daemon if there is
+   none running.  Otherwise it connects to the running daemon and sends the
+   it information to open a window in the daemon's process, and the new
+   instance then terminates.
+ * With the daemon changes, network and network proxy code could be unified.
+   This should improve the robustness of electrum's networking.
+ * Networking was rewritten to multiplex use select(), so all server
+   communication is handled by a single thread rather than a thread
+   per server connection.  Moreover, the synchronizer, verifier, and
+   exchange rate plugin now run as separate jobs within the networking
+   thread instead of as their own threads.  The elimination of so many
+   threads should lead to reduced lock contention and CPU usage.
+ * Various bugfixes.
+
 # Release 2.4.4
  * fix bug with trustedcoin plugin