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/common/rfb/DecodeManager.h b/common/rfb/DecodeManager.h
index 2098063..058d824 100644
--- a/common/rfb/DecodeManager.h
+++ b/common/rfb/DecodeManager.h
@@ -65,7 +65,7 @@
       Rect rect;
       int encoding;
       Decoder* decoder;
-      const ConnParams* cp;
+      const ServerParams* server;
       ModifiablePixelBuffer* pb;
       rdr::MemOutStream* bufferStream;
       Region affectedRegion;