Add modes (sport, cinema, music, etc.)

[jeanprbt]

In solo-mode, user could choose whether to play with all celebrities, or within a sublist of celebrities from a specific field (cinema, sport, music, art, politics and sciences could be a good start). This would require sort the celebrities we currently have in all these categories. We could also sort celebrities according to their era (e.g. 20th century, Middle Age, contemporary, etc).

Also, this issue could include having fine-grained statistics for each category.