===========windows运行gtest=================
  STEP1: 下载cygwin安装,默认在c:cygwin
  STEP2: 下载gtest1.6,解压并拷贝到cygwin的目录下,即c:cygwin的某个子目录下
  STEP3: hack src/gtest.cc:808行的gettimeofday(window没有这个函数,参考http://blog.chinaunix.net/uid-140978-id-3029195.html)
  替换 :gettimeofday(&now, NULL);
  替换成:
  FILETIME ft;
  long long *time64 = (long long *) &ft;
  GetSystemTimeAsFileTime (&ft);
  *time64 -= 116444736000000000LL;
  *time64 /= 10;
  now.tv_sec = *time64 / 1000000;
  now.tv_usec = *time64 % 1000000;
  STEP4: 进入make子目录,去掉Makefile中的后一行的 -lpthread(window无pthread库)
  STEP5: 执行make,生成并运行sample1_unittest.exe,截图略