Implement multi-master queries and heartbeats (#717)

Implement multi-master server list query and multi-master heartbeats. The server list is fetched from multiple masters to improve redundancy, reliability and performance. This improves multiplayer availability by implementing support for using multiple masters.
- The server sends an heartbeat to all masters at once
- The client can query up to 4 masters in parallel depending on their rate

code/server/server.h

@@ -633,14 +633,6 @@ void SV_NET_UpdateClientNetProfileInfo(netprofclient_t* netprofile, int rate);
 void SV_NET_UpdateAllNetProfileInfo();
 void SV_NET_CalcTotalNetProfile(netprofclient_t* netprofile, qboolean server);
 
-//
-// sv_gamespy.c
-//
-void SV_GamespyHeartbeat();
-void SV_ProcessGamespyQueries();
-qboolean SV_InitGamespy();
-void SV_ShutdownGamespy();
-
 #ifdef __cplusplus
 }
 #endif

code/server/sv_init.c

@@ -24,6 +24,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "../client/client.h"
 #include "../qcommon/tiki.h"
 #include "../qcommon/bg_compat.h"
+#include "../gamespy/sv_gamespy.h"
 
 static char last_mapname[ MAX_QPATH ];
 static int g_iSvsTimeFixupCount;