Created by: wvengen
Users of UnifiedNLP's Local-GSM-Backend already have an OpenCellID database on their phone. This PR brings in support for that, plus a fix for the map view that allows it to work with large OCID databases.
When the AIMSICD database is opened, a view is created used for querying OCID. Usually this view is the same as the local database table, but when the other OpenCellID database is found, this view becomes a union of the local and other database.
I found the map view to be choking on the amount of datapoints in my OpenCellID database. This PR also limits the cells loaded in the map view to the area shown, which solves the issue for higher zoom-levels. #466 (closed)