Add internal factions and politics

[guillaume-alvarez]

It is important the player empire is not just a color on the map.

One way to personalize it is to add factions or social groups to the game:

• army leaders
• rich merchants
• cultural elite

Which one is prefered by the people? Which one is in command of the state?

When making decisions (choosing policies or discoveries) the player must know it will advantage one of these groups. The prefered group should provide bonus/malus to the empire, but failing to keep balance between them will also reduce the empire stability (see #19).

These groups might be personnalised, so that the player can ask them their advice, then either follow it or anger them.

A council (ala King of the Dragon Pass) could also be created with members of the different factions.