Get rid of some warnings, mainly unused parameters/variables.

Thanks sparkprime for the patch, see http://code.google.com/p/bullet/issues/detail?id=330

src/BulletCollision/BroadphaseCollision/btBroadphaseInterface.h

@@ -65,7 +65,7 @@ public:
 	virtual void getBroadphaseAabb(btVector3& aabbMin,btVector3& aabbMax) const =0;
 
 	///reset broadphase internal structures, to ensure determinism/reproducability
-	virtual void resetPool(btDispatcher* dispatcher) {};
+	virtual void resetPool(btDispatcher* dispatcher) { (void) dispatcher; };
 
 	virtual void	printStats() = 0;
 

src/BulletCollision/BroadphaseCollision/btDbvt.h

@@ -947,6 +947,7 @@ inline void		btDbvt::rayTestInternal(	const btDbvtNode* root,
 								const btVector3& aabbMax,
 								DBVT_IPOLICY) const
 {
+        (void) rayTo;
 	DBVT_CHECKTYPE
 	if(root)
 	{

src/BulletCollision/BroadphaseCollision/btOverlappingPairCache.h

@@ -457,6 +457,7 @@ public:
 	
 	virtual void	sortOverlappingPairs(btDispatcher* dispatcher)
 	{
+        (void) dispatcher;
 	}