COMP: Set CMake Policy CMP0022 to NEW

Since commit ed6c07d0 (Cleanup CMP0022 and CMP0023 warnings, 2013-08-19)
VTK uses target_link_libraries signatures to set the link interface
without direct manipulation of the old LINK_INTERFACE_LIBRARIES
property.  Set CMP0022 to NEW to avoid warnings about differences due to
generator expressions in INTERFACE_LINK_LIBRARIES, known to be safe.

Change-Id: I0afe5e316846e7883e3d6cb50a1dfa9bad0f6426

CMakeLists.txt

 cmake_minimum_required(VERSION 2.8.7 FATAL_ERROR)
 
+if(POLICY CMP0022)
+  cmake_policy(SET CMP0022 NEW)
+endif()
+
 project(VTK)
 
 # Objective-C++ compile flags, future CMake versions might make this obsolete

Testing/External/CMakeLists.txt

 # This project builds the test directories from all VTK modules as a separate
 # project outside the main VTK build tree as if they were an application.
 cmake_minimum_required(VERSION 2.8.5 FATAL_ERROR)
+
+if(POLICY CMP0022)
+  cmake_policy(SET CMP0022 NEW)
+endif()
+
 project(VTKTestExternal)
 if(VTK_SOURCE_DIR OR VTK_BINARY_DIR)
   message(FATAL_ERROR "This directory may build only outside VTK!")