Adding a docgen page.

Changing dartdoc pointers to docgen.

Merge branch 'master' into docgen

Merge branch 'master' of https://github.com/dart-lang/dartlang.org

Merge branch 'master' of https://github.com/dart-lang/dartlang.org

Adding "Pub" to title of the new transformer page.

BUG=
R=alanknight@google.com, efortuna@google.com

Review URL: https://codereview.appspot.com/71790043
Adding a new tools page.

BUG=
R=kathyw@google.com, sethladd@google.com

Review URL: https://codereview.appspot.com/69930045
Removing dartdoc docs and redirecting to docgen.

BUG=
R=sethladd@google.com

Review URL: https://codereview.appspot.com/72200043
Fix a pja-reported typo
Update Oilpan link in FAQ
Adding a FAQ about setting proxies behind a firewall.

BUG=
R=nweiz@google.com, pquitslund@google.com

Review URL: https://codereview.appspot.com/72650043
remove old images, replace old logo

BUG=

Review URL: https://chromiumcodereview.appspot.com//192953002
Update spec to 1.2

Review URL: https://chromiumcodereview.appspot.com/192753004