Fixed duplicate problem in Client History (1/2)

1. History entries are now indexed by the video's Data and Type, like the rest of the system uses, instead of the URL the client gave.
2. New columns have been added to the cinema_requests SQLite table for the new data.
3. The new system progressively converts over old entries by adding the video type and data to them and attempts to find and destroy duplicates, thus being backward compatible with the old system.