More tactical features add to units

[OptimusShepard]

To increase the need of tactical considerations, there should be different ways to send troops into battle. Therefore the stances of units shall get the following upgrades/bonus

1. Violent: more attack speed, more speed, less armor, less damage
2. Aggressive: more speed, less armor
3. Defensive: more armor, less speed
4. Standground: more armor, more damage (especially for spearman against horseman), less attack speed

Also see #4791

[elexis]

I doubt that attack, armor and speed stats should be linked to the stance. But it has always been planned that formations do these things.

[OptimusShepard]

A single soldier can also crouch behind his shield, even if not as effective as e. g. in a turtle formation. Which is why the bonus should not be too high, but the disadvantage should be as high as in comparable formations. In my opinion, formation and fighting style are not mutually exclusive.

[fatherbushido]

It doesn't really appears related to stance, I will permit myself to close it.