Allow user to create a custom adapter.

[AdamMc331]

Currently the library handles the adapter itself using a cursoradapter. Let's give the user the option to override this - which will also give them freedom to display the suggestion items.

[Mauker1]

I'm thinking of moving this to v 2.0. It's not a minor change at all, and the default CursorAdapter will probably change once we migrate from ListView to RecyclerView (as per #99).

[Mauker1]

The ListView was migrated to a RecyclerView but this adapter change is still pending. I need to make the add/query/remove methods return if the user is using a custom adapter. Also, I'm Pushing this to 2.1.0.