Add new command to create a new polymer entry point (both the HTML
boilerplate and adding the entrypoint to pubspec.yaml).

Review URL: https://codereview.chromium.org//449653002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39008 260f80e4-7a28-3924-810f-c04153c831b5
client -> observatory

R=johnmccutchan@google.com

Review URL: https://codereview.chromium.org//454533002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39009 260f80e4-7a28-3924-810f-c04153c831b5
Bump multivm DEPS

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@39010 260f80e4-7a28-3924-810f-c04153c831b5