Fix sample code in dart:io article

R=kathyw@google.com
BUG=http://dartbug.com/13713

Review URL: https://chromiumcodereview.appspot.com//140683003
who uses dart

BUG=
R=kathyw@google.com

Review URL: https://chromiumcodereview.appspot.com//140683006
Fixes based on comments from the London hackathon users

BUG=
R=kathyw@google.com

Review URL: https://chromiumcodereview.appspot.com/139703002
Add section for additional community resources

Staged:

https://chinese-dot-dart-lang.appspot.com/support/

R=sethladd@google.com

Review URL: https://chromiumcodereview.appspot.com/134633003
add image for who uses dart

BUG=

Review URL: https://chromiumcodereview.appspot.com//138803004
Adding sipXecs
Merge pull request #287 from dhubler/patch-1

Adding sipXecs
dart -> Dart

R=sethladd@google.com

Review URL: https://chromiumcodereview.appspot.com/142143002
Removed debugging statements.

Adding analytics for SDK and Dartium downloads.

BUG=
R=sethladd@google.com

Review URL: https://codereview.appspot.com/53320043