Update CMake for 3.12 and newer

 - Get rid of dev warning about [policy CMP0075]
 - See documentation of [CMake policies] for additional info

[policy CMP007]: https://cmake.org/cmake/help/latest/policy/CMP0075.html
[CMake policies]: https://cmake.org/cmake/help/latest/manual/cmake-policies.7.html

Author: zbeekman

CMakeLists.txt

@@ -1,5 +1,9 @@
 cmake_minimum_required(VERSION 3.2)
 
+if(POLICY CMP0075)
+  cmake_policy(SET CMP0075 NEW)
+endif()
+
 # Set the type/configuration of build to perform
 set ( CMAKE_CONFIGURATION_TYPES "Debug" "Release" "MinSizeRel" "RelWithDebInfo" "CodeCoverage" )
 set ( CMAKE_BUILD_TYPE "Release"