BUG: Disable Plugin test until it works everywhere.

Source/CMakeLists.txt

@@ -986,6 +986,8 @@ IF(BUILD_TESTING)
     --test-command executable
     )
 
+  # Disable this test by default until it works everywhere.
+  IF(CMAKE_TEST_ENABLE_Plugin)
   ADD_TEST(Plugin ${CMAKE_CTEST_COMMAND}
     --build-and-test
     "${CMake_SOURCE_DIR}/Tests/Plugin"
@@ -995,6 +997,7 @@ IF(BUILD_TESTING)
     --build-makeprogram ${CMAKE_TEST_MAKEPROGRAM}
     --build-two-config
     --test-command bin/example)
+  ENDIF(CMAKE_TEST_ENABLE_Plugin)
 
   IF(NOT CMAKE_TEST_DIFFERENT_GENERATOR)
     ADD_TEST(kwsys ${CMAKE_CTEST_COMMAND}