Merge pull request #1062 from SonarDesignInc/master

Adding SonarDesign and Lumo to who-uses-dart.html
Added 'Children of Ur'

Attempt 2, links should work this time.
Merge pull request #1064 from ppvk/patch-1

Added 'Children of Ur'
Add "transformers" line to pubspec.yaml excerpts

Staged at:
https://1065-dot-dart-lang.appspot.com/polymer/#installing-polymerdart
https://1065-dot-dart-lang.appspot.com/polymer/using-elements/

BUG=https://github.com/dart-lang/www.dartlang.org/issues/1065
R=sethladd@google.com

Review URL: https://chromiumcodereview.appspot.com/613683005
Adding info about using pub global activate to add a package's executables to your path.

BUG=
R=rnystrom@google.com

Review URL: https://codereview.appspot.com/150990043