Adds a database.

This is a really simple map. Calls to it just check if the key exists
and return a bool. In case of a false it adds the key.
The key is just a string which might or might not be sufficient.
Adds the database for checking new channels/items.

In this iteration the key passed to the database is the Title which is
obviously silly.
I'm still looking for a configurable way of generating the unique key.