use size_t instead of int, for allocator

added hashtable based PairManager, thanks Pierre Terdiman and Erin Catto
improved friction in 'cachefriendly' solver
moved 'refreshcontactpoints' into collision detection, instead of solver
avoid linear search for contact manifolds, by storing an index
ignore margin for sphere shape (its entire radius is already margin)
avoid alignment checks in BVH serialization, they don't compile on 64-bit architectures
made 'bomb' box more heavy

src/LinearMath/btAlignedAllocator.cpp

@@ -19,7 +19,7 @@ subject to the following restrictions:
 #if defined (BT_HAS_ALIGNED_ALOCATOR)
 
 #include <malloc.h>
-void*	btAlignedAlloc	(int size, int alignment)
+void*	btAlignedAlloc	(size_t size, int alignment)
 {
 	void* ptr = _aligned_malloc(size,alignment);
 //	printf("btAlignedAlloc %d, %x\n",size,ptr);
@@ -41,7 +41,7 @@ void	btAlignedFree	(void* ptr)
 int numAllocs = 0;
 int numFree = 0;
 
-void*	btAlignedAlloc	(int size, int alignment)
+void*	btAlignedAlloc	(size_t size, int alignment)
 {
 	numAllocs++;
 	return memalign(alignment, size);
@@ -55,7 +55,7 @@ void	btAlignedFree	(void* ptr)
 
 #else
 
-void*	btAlignedAlloc	(int size, int alignment)
+void*	btAlignedAlloc	(size_t size, int alignment)
 {
  void *ret;
   char *real;

src/LinearMath/btAlignedAllocator.h

@@ -22,7 +22,7 @@ subject to the following restrictions:
 
 #include "btScalar.h"
 
-void*	btAlignedAlloc	(int size, int alignment);
+void*	btAlignedAlloc	(size_t size, int alignment);
 
 void	btAlignedFree	(void* ptr);
 

src/LinearMath/btPoolAllocator.h

@@ -61,6 +61,17 @@ public:
         return result;
 	}
 
+	bool validPtr(void* ptr)
+	{
+		if (ptr) {
+			if (((unsigned char*)ptr >= m_pool && (unsigned char*)ptr < m_pool + m_maxElements * m_elemSize))
+			{
+				return true;
+			}
+		}
+		return false;
+	}
+
 	void	free(void* ptr)
 	{
 		 if (ptr) {

src/LinearMath/btScalar.h

@@ -288,6 +288,13 @@ SIMD_FORCE_INLINE float btSelect(unsigned condition, float valueIfConditionNonZe
 #endif
 }
 
+template<typename T> inline void btSwap(T& a, T& b)
+{
+	T tmp = a;
+	a = b;
+	b = tmp;
+}
+
 
 //PCK: endian swapping functions
 SIMD_FORCE_INLINE unsigned btSwapEndian(unsigned val)