delete test commit, open openmp switch (#1650)

CMakeLists.txt

 cmake_minimum_required(VERSION 3.0.0)
 
 # basic build option
-option(USE_OPENMP       "build with openmp support"      OFF)
+option(USE_OPENMP       "build with openmp support"      ON)
 option(USE_EXCEPTION    "build with exception"           ON)
 option(WITH_LOGGING     "print logging for debug"        OFF)
 option(WITH_SYMBOL      "build with all symbols"         ON) # turn off if use jni or ios io