Get global database and work locally
====================================
Actually all queries are on-line. But the whole database can be retrieved and
stored in local, so all operation can be performed off-line.

Doing it requires to implement the search in local. We should explore if either
moving to this approach or even creating a new derivative plugin that follows
this off-line approach worths it.


Implement childcount
====================
Implementing childcount would require, for each result doing another search and
retrieve all children, counting them.


Limit search-rate
=================
Jamendo terms of use states that applications should be limited to 1 query per
second. Some kind of control should be needed in the plugin.


Limit requested elements
========================
User can request any arbitrary number of elements, and this request is propagated to Jamendo.

Nevertheless, it would be better to break the request in smaller chunks, so
though user requests, for instance, 1000 albums, we do the query in steps of 25
elements.
