Revert "Temporary fix for Netdate ("AUg" instead of "Aug")."

This fix is no longer needed with the latest ocamlnet.
This reverts commit 18acc3b74f73ca7974ea0714c0bd2ac6f59bcf85.
Require netstring >= 3.7.3
Merge github.com:ocaml/ocaml.org into redesign

Conflicts:
	_oasis