Updating the Root.cmake to fit the CMP0153 policy since the

"exec_program" command and has been deprecated since CMake 3.0

NPLib/ressources/CMake/Root.cmake

@@ -15,7 +15,7 @@ if(NPTOOL_ROOT_CONFIG MATCHES "NOTFOUND")
   message(FATAL_ERROR "ROOT is not found, check your installation")
 endif()
 
-exec_program(${NPTOOL_ROOT_CONFIG} ARGS "--version" OUTPUT_VARIABLE NPTOOL_ROOT_VERSION)
+execute_process(COMMAND "${NPTOOL_ROOT_CONFIG} ARGS \"--version\" OUTPUT_VARIABLE NPTOOL_ROOT_VERSION")
 # now parse the parts of the user given version string into variables
 string(REGEX REPLACE "^([0-9]+)\\.[0-9][0-9]+\\/[0-9][0-9]+" "\\1" req_root_major_vers "${ROOT_MIN_VERSION}")
 string(REGEX REPLACE "^[0-9]+\\.([0-9][0-9])+\\/[0-9][0-9]+.*" "\\1" req_root_minor_vers "${ROOT_MIN_VERSION}")
@@ -39,15 +39,15 @@ endif()
 set(ROOT_LIBRARIES dl Gui Core RIO Net Hist Gpad Tree Physics MathCore Thread ASImage)
 
 # Lib directories
-exec_program(${NPTOOL_ROOT_CONFIG} ARGS "--libdir" OUTPUT_VARIABLE ROOT_LIBRARY_DIR)
+execute_process(COMMAND "${NPTOOL_ROOT_CONFIG} ARGS \"--libdir\" OUTPUT_VARIABLE ROOT_LIBRARY_DIR")
 link_directories( ${ROOT_LIBRARY_DIR})  
 
 # Include directories
-exec_program(${NPTOOL_ROOT_CONFIG} ARGS "--incdir" OUTPUT_VARIABLE ROOT_INCLUDE_DIR)
+execute_process(COMMAND "${NPTOOL_ROOT_CONFIG} ARGS \"--incdir\" OUTPUT_VARIABLE ROOT_INCLUDE_DIR")
 include_directories(SYSTEM ${ROOT_INCLUDE_DIR})  
 
 # Get the compilator flag from root to assure consistancy
-exec_program(${NPTOOL_ROOT_CONFIG} ARGS "--cflags" OUTPUT_VARIABLE NPTOOL_ROOT_CFLAGS )
+execute_process(COMMAND "${NPTOOL_ROOT_CONFIG} ARGS \"--cflags\" OUTPUT_VARIABLE NPTOOL_ROOT_CFLAGS")
 if(CMAKE_CXX_FLAGS)
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${NPTOOL_ROOT_CFLAGS}")
 else()