CMake: Migrate detection of libtar

dtool/Config.cmake

@@ -491,13 +491,6 @@ option(HAVE_VIDEO4LINUX
   "Set this to enable webcam support on Linux." ${IS_LINUX})
 
 
-# Is libtar installed, and where?
-find_package(Tar QUIET)
-
-package_option(TAR
-  "This is used to optimize patch generation against tar files.")
-
-
 # TODO: FFTW2
 # Is libfftw installed, and where?
 #find_package(FFTW2 QUIET)

dtool/LocalSetup.cmake

@@ -190,12 +190,6 @@ endif()
 # Now go through all the packages and report whether we have them.
 show_packages()
 
-if(HAVE_TAR)
-  message("+ libtar")
-else()
-  message("- Did not find libtar")
-endif()
-
 if(HAVE_FFTW)
   message("+ fftw")
 else()

dtool/Package.cmake

@@ -65,6 +65,14 @@ find_package(TIFF QUIET)
 package_option(TIFF "Enable support for loading .tif images.")
 config_package(TIFF "libtiff")
 
+#
+# ------------ LIBTAR ------------
+#
+find_package(Tar QUIET)
+package_option(TAR
+  "This is used to optimize patch generation against tar files.")
+config_package(TAR "libtar")
+
 # Find and configure Miles Sound System
 find_package(Miles QUIET)
 #config_package(RAD_MSS "Miles Sound System")