Handle tuners without DeviceAuth strings better

[djp952]

Handle tuners without DeviceAuth strings better

[djp952]

EPG queries have been updated to deal with this, but nothing else yet.

[djp952]

A viable method has been determined to check the individual tuner DeviceAuth strings that doesn't incur downloading a bunch of data that will be discarded. My plan would be to make checking the DeviceAuth(s) as part of PVR startup, probably as a scheduled task, and this would allow me to either block tasks that will never work, or in the case of one/some auths being good, alter the user that there may be a problem with their subscription and/or registration.

Idea was from signcarver on the SD forums, and I think it will work out.

[djp952]

Note to self : the code added to allow a "no tuners" condition has also become problematic and should be solved at the same time. If there are legitimately no tuners, like the network is messed up, the old device auth codes will still be used, and just cause a bunch of 403 errors. The new method should separate out the authorization(s) from the tuner(s) so if they fail to refresh the backend won't get called at all.

[djp952]

Fixed for version 2.0.0. Implementation uses the 'account' API during discovery to determine if the user has DVR authorization or not. All device auth strings are validated to be non-null and now are sent into the database API calls from the PVR layer, providing the opportunity to block/log/throw as appropriate.