o Minor bugfixes (linux seccomp2 sandbox):
    - Makes the seccomp sandbox allow the correct syscall for opendir
      according to the running glibc version. The opendir function
      either uses open or openat but the current code does not
      differenciate between opendir and open calls. This adds a new
      seccomp sandbox rule for opendir. This fixes crashes when 
      reloading torrc with sandbox enabled when running on glibc
      2.15 to 2.21 and 2.26. Patch from Daniel Pinto. Fixes bug 40020; 
      bugfix on 0.3.5.11.