TODO for the 0.4 version of swac-get
* add authors, copyright, license, description and count fields in `packages` and `available_packages` table => DONE
* manage the upgrading of the database structure from the 0.3 version => DONE
* rewrite the SQLite C++ binding => DONE
* check version  number for "swac-get upgrade" command => DONE

TODO for the 0.5 version of swac-get
* use GOptions for the command line parser
* Replace std::string by Glib::ustring
* change class name Tswac_index => SwacIndex etc...
* replace libxml by libxml++
* fill the information about packages using the local default language
* Internationalization
* add a "download" command
* add a field `edited` in the `sounds` table
* add a "check" command (check wether local packages are still present on the hard drive)
