Set policy CMP0025 to NEW while building CMake itself

CMake is aware of the policy's NEW behavior and the AppleClang compiler
id.  Set the policy to NEW explicitly to avoid the warning and get the
NEW behavior.

Also teach the RunCMake test infrastructure to build tests with
-DCMAKE_POLICY_DEFAULT_CMP0025=NEW to avoid the policy warning
in test output that must match specific regular expressions.

CMakeLists.txt

@@ -11,6 +11,9 @@
 #=============================================================================
 cmake_minimum_required(VERSION 2.8.2 FATAL_ERROR)
 set(CMAKE_LEGACY_CYGWIN_WIN32 0) # Remove when CMake >= 2.8.4 is required
+if(POLICY CMP0025)
+  cmake_policy(SET CMP0025 NEW)
+endif()
 project(CMake)
 
 if(CMAKE_BOOTSTRAP)

Source/kwsys/CMakeLists.txt

@@ -85,6 +85,9 @@
 # written.
 
 CMAKE_MINIMUM_REQUIRED(VERSION 2.6.3 FATAL_ERROR)
+IF(POLICY CMP0025)
+  CMAKE_POLICY(SET CMP0025 NEW)
+ENDIF()
 
 #-----------------------------------------------------------------------------
 # If a namespace is not specified, use "kwsys" and enable testing.

Tests/RunCMake/RunCMake.cmake

@@ -36,6 +36,9 @@ function(run_cmake test)
   if(NOT DEFINED RunCMake_TEST_OPTIONS)
     set(RunCMake_TEST_OPTIONS "")
   endif()
+  if(APPLE)
+    list(APPEND RunCMake_TEST_OPTIONS -DCMAKE_POLICY_DEFAULT_CMP0025=NEW)
+  endif()
   execute_process(
     COMMAND ${CMAKE_COMMAND} "${RunCMake_TEST_SOURCE_DIR}"
               -G "${RunCMake_GENERATOR}"

Utilities/cmcurl/CMakeLists.txt

@@ -1,4 +1,7 @@
 CMAKE_MINIMUM_REQUIRED(VERSION 2.6.3 FATAL_ERROR)
+IF(POLICY CMP0025)
+  CMAKE_POLICY(SET CMP0025 NEW)
+ENDIF()
 PROJECT(LIBCURL C)
 
 # Setup package meta-data