fix dead link to args library

old link does not work. I guess it's this one.
Adding back credits to Peter Ahé who were stripped by Photoshop.
Adding image metadata adding copyright to Google.
Updating schema.org event data so that it's imported nicely in G+.
Adding generated files from copyedit PR #1155
Adding 2 more option for images in G+ imports.
Merge pull request #1159 from nicolasgarnier/dartsummit-update

Dartsummit site update
Book improvements:
* Convert book notes to site format
* Run dartfmt on the samples

Staged at URLs like:
https://book-dot-dart-lang.appspot.com/docs/dart-up-and-running/ch02.html

R=shaza@google.com

Review URL: https://chromiumcodereview.appspot.com/716263002
In keyword table, change symbols to numbers

Staged at:
https://table-dot-dart-lang.appspot.com/docs/dart-up-and-running/ch02.html#keywords

BUG= https://github.com/dart-lang/www.dartlang.org/issues/1148
R=shaza@google.com

Review URL: https://chromiumcodereview.appspot.com/754033003
Merge pull request #1150 from michals/patch-2

fix dead link to args library