message: Added WallClock class
  * Added WallClock class to provide much faster xxxNowInSec() and xxxNowInMilliSec() methods
  * Addressed and comments
  * Doubled the performance and rebased
  Thanks to idea, I changed all the division to multiplication in the PR to further cut the latency by 50%
diff: @@ -59,8 +59,13 @@ if(NOT CMAKE_BUILD_TYPE)
  set(CMAKE_BUILD_TYPE "Debug")
  endif(NOT CMAKE_BUILD_TYPE)
  -message(STATUS "CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}, "
  - "options: Debug, Release, RelWithDebInfo, MinSizeRel")
  +if(NOT ${CMAKE_BUILD_TYPE} STREQUAL "Debug")
  + message(STATUS "Set macro _FORTIFY_SOURCE=2")
  + add_definitions(-D_FORTIFY_SOURCE=2)
  +endif()
  +
  +message(STATUS "CMAKE_BUILD_TYPE = ${CMAKE_BUILD_TYPE} "
  + "(Options are: Debug, Release, RelWithDebInfo, MinSizeRel)")
  set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "_build")
  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "_build")
  