CMake: Turn OFF HAVE_CARBON by default

.travis.yml

@@ -90,7 +90,7 @@ script:
       export PY2_CMAKE_ARGS=-DPYTHON_EXECUTABLE=/usr/local/Frameworks/Python.framework/Versions/2.7/bin/python
     fi
 
-    cmake -DHAVE_CARBON=NO -DBUILD_METALIBS=$BUILD_METALIBS \
+    cmake -DBUILD_METALIBS=$BUILD_METALIBS \
     -DCOMPOSITE_SOURCE_LIMIT=$COMPOSITE_SOURCE_LIMIT \
     -DOPENSSL_ROOT_DIR=/usr/local/opt/openssl $PY2_CMAKE_ARGS ..
   else

dtool/Config.cmake

@@ -532,13 +532,10 @@ else()
   option(HAVE_WGL "Enable WGL.  Requires OpenGL on Windows." OFF)
 endif()
 
-if(IS_OSX)
-  option(HAVE_COCOA "Enable Cocoa. Requires Mac OS X." ON)
-  option(HAVE_CARBON "Enable Carbon. Requires Mac OS X." ON)
-else()
-  option(HAVE_COCOA "Enable Cocoa. Requires Mac OS X." OFF)
-  option(HAVE_CARBON "Enable Carbon. Requires Mac OS X." OFF)
-endif()
+cmake_dependent_option(HAVE_COCOA "Enable Cocoa. Requires Mac OS X." ON
+  "APPLE" OFF)
+cmake_dependent_option(HAVE_CARBON "Enable Carbon. Requires Mac OS X." OFF
+  "APPLE" OFF)
 
 #
 # <<<<<< Insert the rest of the Config.pp