Split out ServerParams from ConnParams

We need to track different things in the server and client, so
separate things to two independent structures to keep things more
clear.
diff --git a/tests/decperf.cxx b/tests/decperf.cxx
index 24f6604..056848a 100644
--- a/tests/decperf.cxx
+++ b/tests/decperf.cxx
@@ -85,7 +85,9 @@
 {
   CConnection::setDesktopSize(w, h);
 
-  setFramebuffer(new rfb::ManagedPixelBuffer(filePF, cp.width(), cp.height()));
+  setFramebuffer(new rfb::ManagedPixelBuffer(filePF,
+                                             server.width(),
+                                             server.height()));
 }
 
 void CConn::setPixelFormat(const rfb::PixelFormat& pf)