Increase the client/server update rate to 125 Hz

This decreases effective latency significantly by making clients
and servers sending and receiving updates sooner. This increases
network traffic by a factor of 3, but it should be manageable
on today's networks.

The average game-induced latency (on top of network lag) should
now be 8 ms instead of 40 ms.

See https://extra-a.github.io/#bnet for more information.

src/game/client.cpp

@@ -2215,7 +2215,7 @@ namespace client
     void c2sinfo(bool force) // send update to the server
     {
         static int lastupdate = -1000;
-        if(totalmillis-lastupdate < 40 && !force) return;    // don't update faster than 25fps
+        if(totalmillis-lastupdate < 8 && !force) return;    // don't update faster than 125 FPS
         lastupdate = totalmillis ? totalmillis : 1;
         sendpositions();
         sendmessages();

src/game/server.cpp

@@ -5932,7 +5932,8 @@ namespace server
     {
         if(clients.empty() || (!hasnonlocalclients() && !demorecord)) return false;
         enet_uint32 millis = enet_time_get()-lastsend;
-        if(millis < 40 && !force) return false;
+        // Update at 125 Hz. Higher update rates result in lower effective latency.
+        if(millis < 8 && !force) return false;
         bool flush = buildworldstate();
         lastsend += millis - (millis%40);
         return flush;