Solves a bug in GROUP:IsPartlyInZone()

If only the first UNITs of the GROUP where outside the ZONE, the function would still return false
This behaviour is fixed by this commit.

Moose Development/Moose/Wrapper/Group.lua

@@ -555,22 +555,23 @@ end
 function GROUP:IsPartlyInZone( Zone )
   self:F2( { self.GroupName, Zone } )
   
-  local PartlyInZone = false
+  local IsOneUnitInZone = false
+  local IsOneUnitOutsideZone = false
   
   for UnitID, UnitData in pairs( self:GetUnits() ) do
     local Unit = UnitData -- Wrapper.Unit#UNIT
     if Zone:IsVec3InZone( Unit:GetVec3() ) then
-      PartlyInZone = true
+      IsOneUnitInZone = true
     else
-      -- So, if there were groups in the zone found, and suddenly one NOT in the zone, 
-      -- then the group is partialy in the zone :-)
-      if PartlyInZone == true then
-        return true
-      end
+      IsOneUnitOutsideZone = true
     end
   end
   
-  return false
+  if IsOneUnitInZone and IsOneUnitOutsideZone then
+    return true
+  else
+    return false
+  end
 end
 
 --- Returns true if none of the group units of the group are within a @{Zone}.