Rename ConnParams to ClientParams

Now that we've split out server state to ServerParams, ConnParams
only contains state for a client. Rename the class and variables
to reflect this.
diff --git a/common/rfb/TightJPEGEncoder.cxx b/common/rfb/TightJPEGEncoder.cxx
index 38cb4eb..7557538 100644
--- a/common/rfb/TightJPEGEncoder.cxx
+++ b/common/rfb/TightJPEGEncoder.cxx
@@ -76,15 +76,15 @@
 
 bool TightJPEGEncoder::isSupported()
 {
-  if (!conn->cp.supportsEncoding(encodingTight))
+  if (!conn->client.supportsEncoding(encodingTight))
     return false;
 
   // Any one of these indicates support for JPEG
-  if (conn->cp.qualityLevel != -1)
+  if (conn->client.qualityLevel != -1)
     return true;
-  if (conn->cp.fineQualityLevel != -1)
+  if (conn->client.fineQualityLevel != -1)
     return true;
-  if (conn->cp.subsampling != -1)
+  if (conn->client.subsampling != -1)
     return true;
 
   // Tight support, but not JPEG