Update to C++ 14 standard and increase cmake version

Author: feliwir

CMakeLists.txt

@@ -1,23 +1,7 @@
 ### ---[ PCL global CMake
-cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.1 FATAL_ERROR)
 
-if(POLICY CMP0017)
-  # Do not include files in CMAKE_MODULE_PATH from files
-  # in CMake module directory. Fix MXE build
-  cmake_policy(SET CMP0017 NEW)
-endif()
-
-if(POLICY CMP0020 AND (WIN32 AND NOT MINGW))
-  cmake_policy(SET CMP0020 NEW) # Automatically link Qt executables to qtmain target on Windows
-endif()
-
-if(POLICY CMP0048)
-  cmake_policy(SET CMP0048 OLD) # do not use VERSION option in project() command
-endif()
-
-if(POLICY CMP0054)
-  cmake_policy(SET CMP0054 OLD) # Silent warnings about quoted variables
-endif()
+set(CMAKE_CXX_STANDARD 14)
 
 set(CMAKE_CONFIGURATION_TYPES "Debug;Release" CACHE STRING "possible configurations" FORCE)