#2 Archer related AI Tweaks

[RainCT (Siegfried Gevatter)]

Isn't really a bug but I decided to put it here :P

- If the archers are fighting side by side with sword-men, in close combat, make them move backwards, so they have some distance to the one they are shooting at.

- Make the sword-men protect the archers if they get attacked in close range, then sword-men close should turn away from their enemy and kill the close-combat unit that is killing the archer (if you implement the Guard feature -http://sourceforge.net/tracker/index.php?func=detail&aid=1634233&group_id=170510&atid=854491- this could be left out).