message: Enable ccache in top CMakeLists.txt
diff: @@ -2,6 +2,13 @@ cmake_minimum_required(VERSION 3.9)
  set(CMAKE_CXX_STANDARD 17)
  set(CMAKE_CXX_STANDARD_REQUIRED ON)
  set(CMAKE_POSITION_INDEPENDENT_CODE ON)
  +
  +find_program(CCACHE_PROGRAM ccache)
  +if(CCACHE_PROGRAM)
  + message(STATUS "CCache enabled")
  + set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_PROGRAM}")
  +endif()
  +
  project(Ripes CXX)
  if(NOT CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
  