+ disable perturbation for btConvexPlaneCollisionAlgorithm, it introduces artifacts (additional points cause spheres/cylinders and other curved objects to move)

+ applied patch to mix double/single precision meshes independent from double/single precision Bullet build
Thanks to Ole for the patch, http://code.google.com/p/bullet/issues/detail?id=213
+ re-enable warming starting in constraint solver, it was disabled by accident
+ fix btConvexHullShape constructor, so accept vertices with non-16-byte striding
Thanks Shawn Baird for report and fix: http://code.google.com/p/bullet/issues/detail?id=204

src/BulletCollision/CollisionDispatch/btConvexPlaneCollisionAlgorithm.h

@@ -60,8 +60,8 @@ public:
 		int m_minimumPointsPerturbationThreshold;
 			
 		CreateFunc() 
-			: m_numPerturbationIterations(3),
-			m_minimumPointsPerturbationThreshold(3)
+			: m_numPerturbationIterations(1),
+			m_minimumPointsPerturbationThreshold(1)
 		{
 		}