Add and wire LordBob's new Knight portrait, update portrait credits.

data/core/images/portraits/ARTISTS

@@ -62,6 +62,7 @@ Human Loyalists:
     Bowman
     Longbowman
     Master Bowman
+    Knight
 
 
 thespaceinvader/Philip Barber:

data/core/units/humans/Horse_Knight.cfg

@@ -18,6 +18,18 @@
     usage=fighter
     description= _ "Horsemen of skill and discipline are promoted to Knights. Veterans of combat, they have seen the often-fatal results of a failed charge, and have learnt discretion in its use. Knights, therefore, carry swords in their armament, and practice tactics which, although requiring of much more patience, are less risky than a charge. Their lances are still at the ready, however, and growing experience with these weapons makes them deadlier at the tilt."+{SPECIAL_NOTES}+{SPECIAL_NOTES_CHARGE}
     die_sound=horse-die.ogg
+    [portrait]
+        size=400
+        side="left"
+        mirror="false"
+        image="portraits/humans/transparent/knight.png"
+    [/portrait]
+    [portrait]
+        size=400
+        side="right"
+        mirror="true"
+        image="portraits/humans/transparent/knight.png"
+    [/portrait]
     [attack]
         name=sword
         description=_"sword"