Moves client IDs to a single file

Creates a new javascript source file that contains all client IDs for the web app.  This file also contains an explanation of the reason for having two client IDs.
Changes client ID for Google Drive access

Changes the client ID used for load/save and realtime access.  This has no affect on users as Google Drive does not are which client ID is used to access it.  Only the Cloud Console project matters, and the new client ID belongs to the same cloud console project as the old on.
Merge pull request #62 from jupyter/clientid

Changes to Client IDs