Append CIDs and Versions to Editor update pings

This adds three fields to the update ping query parameter

- A random CID that is persisted in the workspace
- A random UUID that is not persisted
- A URL encoded version string

Tests for CID persistence behaviour have been added
I have verified that appending the query parameters to the URLs does not affect the behaviour

We need to do a manual system test to ensure that this doesn't affect the upgrade behaviour and that the same CID is sent after an upgrade.

R=danrubel@google.com

Review URL: https://codereview.chromium.org//642393002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41060 260f80e4-7a28-3924-810f-c04153c831b5