Replace EHS HTTP server with cpp-httplib

Server/mods/deathmatch/StdInc.h

@@ -34,6 +34,16 @@
     #include <winsock2.h>
     #include <windows.h>
     #include <mmsystem.h>
+#else
+//
+// Non-Windows: provide the Windows Sleep() spelling used throughout this
+// module. This used to be supplied transitively by the EHS vendor headers
+// (vendor/ehs/socket.h); now that EHS is gone we define it ourselves, matching
+// the equivalent shim in Server/core/StdInc.h.
+    #include <unistd.h>
+    #ifndef Sleep
+        #define Sleep(duration) usleep((duration) * 1000)
+    #endif
 #endif
 
 #include <net/CSimControl.h>

Server/mods/deathmatch/logic/CGame.cpp

@@ -573,6 +573,11 @@ void CGame::DoPulse()
     if (m_pHqComms)
         m_pHqComms->Pulse();
 
+    // Periodic maintenance for the built-in HTTP server (login session and
+    // connection cache upkeep).
+    if (m_pHTTPD)
+        m_pHTTPD->HttpPulse();
+
     CLOCK_CALL1(m_pFunctionUseLogger->Pulse(););
     CLOCK_CALL1(m_lightsyncManager.DoPulse(););