Don't parse FLTK arguments using Fl::arg; handle -display as other options

Fl::arg accepts several arguments which we are not documenting. Also,
it accepts a -geometry argument, which clashes with our own -geometry
option.

vncviewer/parameters.cxx

@@ -134,6 +134,9 @@ BoolParameter sendPrimary("SendPrimary",
                           "Send the primary selection to the "
                           "server as well as the clipboard selection",
                           true);
+StringParameter display("display",
+			"Specifies the X display on which the VNC viewer window should appear.",
+			"");
 #endif
 
 StringParameter menuKey("MenuKey", "The key which brings up the popup menu",

vncviewer/parameters.h

@@ -55,6 +55,7 @@ extern rfb::BoolParameter setPrimary;
 extern rfb::BoolParameter sendClipboard;
 #if !defined(WIN32) && !defined(__APPLE__)
 extern rfb::BoolParameter sendPrimary;
+extern rfb::StringParameter display;
 #endif
 
 extern rfb::StringParameter menuKey;

vncviewer/vncviewer.cxx

@@ -495,9 +495,6 @@ int main(int argc, char** argv)
   }
 
   for (int i = 1; i < argc;) {
-    if (Fl::arg(argc, argv, i))
-      continue;
-
     if (Configuration::setParam(argv[i])) {
       i++;
       continue;
@@ -522,6 +519,9 @@ int main(int argc, char** argv)
   mkvnchomedir();
 
 #if !defined(WIN32) && !defined(__APPLE__)
+  if (strcmp(display, "") != 0) {
+    Fl::display(display);
+  }
   fl_open_display();
   XkbSetDetectableAutoRepeat(fl_display, True, NULL);
 #endif