Grüü apparition fixed (and commits squashed)

This, instead of killing Grüü, moves him along with the others to participate
in the conversation, and also switches him to side 1 (this side is temporary
and only for narrative purposes, later on turn 7 he switches to side 4 again).

Grüü is correctly stored on the variable when the conversation ends, and
restored later on turn 7.

(cherry picked from commit cccd562cc5)
(cherry picked from commit 34a5cce2b0)
(cherry picked from commit f231348900)
(cherry picked from commit 89dbd2d373)

data/campaigns/Son_Of_The_Black_Eye/scenarios/14_Back_Home.cfg

@@ -196,11 +196,14 @@
         name=prestart
 
         {RENAME_IF_DEAD thelarion_dead Thelarion (_"Valan")}
-
-        [kill]
-            id=Grüü
-            side=4
-        [/kill]
+        [modify_unit]
+            [filter]
+                id=Grüü
+            [/filter]
+            x=5
+            y=34
+            side=1
+        [/modify_unit]
     [/event]
 
     {GOT_THE_GREAT_HORDE 1,2,3,4}
@@ -241,9 +244,6 @@
     [event]
         name=start
 
-        [recall]
-            id=Grüü
-        [/recall]
         [recall]
             id=Jetto
         [/recall]