Adding implementation for openat(2) needed by OpenSSH sshd
Fixing the unbounded wait for select(2)
- NULL value for the timeout argument to select(2) represents "block indefinitely".
  But the same is represented in OCaml's Unix.select by a negative value for the 4th parameter.
Merge remote-tracking branch 'upstream/master'
Framework implementation for getsockopt(2), minor changes to setsockopt(2)
- Added in as many socket options as supported by the Unix module to getsockopt(2)
- Added support for SO_LINGER, SO_RCVTIMEO, SO_SNDTIMEO in setsockopt(2)
Framework implementation for shutdown(2)
Framework implementation for SOL_SOCKET level options in setsockopt(2)
Minor changes to adhere to line length limit and remove unneeded comments
Merge pull request #3 from vaibhavbsharma/master

Framework implementation for openat(2), getsockopt(2), setsockopt(2), shutdown(2)