CMake: Migrate over VRPN detection

dtool/Config.cmake

@@ -466,13 +466,6 @@ option(HAVE_VIDEO4LINUX
   "Set this to enable webcam support on Linux." ${IS_LINUX})
 
 
-# Is VRPN installed, and where?
-find_package(VRPN QUIET)
-
-package_option(VRPN
-  "Enables support for connecting to VRPN servers.")
-
-
 # Is ZLIB installed, and where?
 find_package(ZLIB QUIET)
 

dtool/LocalSetup.cmake

@@ -189,12 +189,6 @@ endif()
 # Now go through all the packages and report whether we have them.
 show_packages()
 
-if(HAVE_VRPN)
-  message("+ VRPN")
-else()
-  message("- Did not find VRPN")
-endif()
-
 if(HAVE_ZLIB)
   message("+ zlib")
 else()

dtool/Package.cmake

@@ -123,6 +123,18 @@ else()
 endif()
 config_package(CG "Nvidia Cg Shading Language" "${cg_apis}")
 
+#
+# ------------ VRPN ------------
+#
+
+find_package(VRPN QUIET)
+
+package_option(VRPN
+  "Enables support for connecting to VRPN servers. This is only needed if you
+  are building Panda3D for a fixed VRPN-based VR installation.")
+
+config_package(VRPN "VRPN")
+
 # Find and configure Miles Sound System
 find_package(Miles QUIET)
 #config_package(RAD_MSS "Miles Sound System")