Get rid of SocketServer::checkTimeouts()

It doesn't belong on each socket server object as timers are global.
Force implementations to call the Timer system directly instead,
avoiding any middle men.

common/network/Socket.h

     //   This is only necessary if the Socket has been put in non-blocking
     //   mode and needs this callback to flush the buffer.
     virtual void processSocketWriteEvent(network::Socket* sock) = 0;
-
-    // checkTimeouts() allows the server to check socket timeouts, etc.  The
-    //   return value is the number of milliseconds to wait before
-    //   checkTimeouts() should be called again.  If this number is zero then
-    //   there is no timeout and checkTimeouts() should be called the next time
-    //   an event occurs.
-    virtual int checkTimeouts() = 0;
   };
 
 }

common/rfb/VNCServerST.cxx

   throw rdr::Exception("invalid Socket in VNCServerST");
 }
 
-int VNCServerST::checkTimeouts()
-{
-  int timeout = 0;
-
-  soonestTimeout(&timeout, Timer::checkTimeouts());
-  
-  return timeout;
-}
-
-
 // VNCServer methods
 
 void VNCServerST::blockUpdates()

common/rfb/VNCServerST.h

     //   Flush pending data from the Socket on to the network.
     virtual void processSocketWriteEvent(network::Socket* sock);
 
-    // checkTimeouts
-    //   Returns the number of milliseconds left until the next idle timeout
-    //   expires.  If any have already expired, the corresponding connections
-    //   are closed.  Zero is returned if there is no idle timeout.
-    virtual int checkTimeouts();
-
 
     // Methods overridden from VNCServer
 

unix/x0vncserver/x0vncserver.cxx

         }
       }
 
-      soonestTimeout(&wait_ms, server.checkTimeouts());
+      soonestTimeout(&wait_ms, Timer::checkTimeouts());
 
       tv.tv_sec = wait_ms / 1000;
       tv.tv_usec = (wait_ms % 1000) * 1000;
         }
       }
 
-      server.checkTimeouts();
+      Timer::checkTimeouts();
 
       // Client list could have been changed.
       server.getSockets(&sockets);

unix/xserver/hw/vnc/XserverDesktop.cc

     }
 
     // Trigger timers and check when the next will expire
-    int nextTimeout = server->checkTimeouts();
+    int nextTimeout = Timer::checkTimeouts();
     if (nextTimeout > 0 && (*timeout == -1 || nextTimeout < *timeout))
       *timeout = nextTimeout;
   } catch (rdr::Exception& e) {

win/rfb_win32/SocketManager.cxx

 #include <winsock2.h>
 #include <list>
 #include <rfb/LogWriter.h>
+#include <rfb/Timer.h>
 #include <rfb_win32/SocketManager.h>
 
 using namespace rfb;
 
   std::map<HANDLE,ListenInfo>::iterator i;
   for (i=listeners.begin(); i!=listeners.end(); i++)
-    soonestTimeout(&timeout, i->second.server->checkTimeouts());
+    soonestTimeout(&timeout, Timer::checkTimeouts());
 
   std::list<network::Socket*> shutdownSocks;
   std::map<HANDLE,ConnInfo>::iterator j, j_next;