moved harcoded constant to config file

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/trunk/supertuxkart@2792 178a84e3-b1eb-0310-8ba1-8eac791a3b58

data/plunger.projectile

@@ -9,7 +9,7 @@
                        ; started to be pulled up 
  (max-height 1.0)      ; height above terrain at which a plunger is 
                        ; started to be pulled back to ground
- (force-updown 1.0)    ; force pushing the spark down 
+ (force-updown 10.0)   ; force pushing the spark down 
                        ; when it's too high above ground
  (force-to-target 15)  ; force with which a spark flies towards
                        ; the nearest kart

src/items/plunger.cpp

@@ -136,7 +136,7 @@ void Plunger::update(float dt)
     hat = std::max(std::min(hat, m_max_height) , m_min_height);
     float delta = m_average_height - hat;
     btVector3 v=getVelocity();
-    v.setZ( /* up-down force */ 10*delta); // FIXME - don't hardcode, move to config file
+    v.setZ( m_st_force_updown[POWERUP_PLUNGER]*delta); // FIXME - don't hardcode, move to config file
     setVelocity(v);
     
 }   // update