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
Push new site design to production

This represents several months of work by many dedicated people.
Many thanks to all those who contributed code, issues and fixes!

Amir
Update README.md

use omd >= 0.7.4 (using a lower version may lead to bugs)
update events

temporarily fixes #301 until #234 can be completed
update "edit this page" link to use master branch (instead of redesign)
Add link for IRC
Merge pull request #306 from lpw25/master

Add link for IRC
change tryocaml to html
Add the "alt" attribute to <img> generated by rss2html
Remove the empty "id" from template tryocaml.html

Fixes https://github.com/ocaml/ocaml.org/issues/305
Activate SSL to be able to get HTTPS URLs.
Generate the "Recent email threads" with rss2html.
Fix after rebase: use consistently "headline_of_post"
Make the "papers" page respect Markdown syntax.

Fixes https://github.com/ocaml/ocaml.org/issues/307
Import email feed from sympa.inria.fr
Process the RSS feed from sympa.inria.fr
Fix the tutorial "Introduction to Gtk" so it shows up.
Update RWO links
Correct formulation

"gives you to access" -> "gives you access to"