Fixed warnings in Bullet/src core library

Thanks Martijn Reuvers from Two Tribes B.V. (www.twotribes.com) for the patch

To make this work more visible, suppress warnings in external libraries in Extras (COLLADA_DOM, libxml and glui contain many warnings)
Added PreprocessorDefinitions: _CRT_SECURE_NO_DEPRECATE;_CRT_NONSTDC_NO_DEPRECATE to vcproj files

src/BulletDynamics/ConstraintSolver/btContactConstraint.cpp

@@ -233,6 +233,12 @@ btScalar resolveSingleFriction(
 }
 
 
+btScalar resolveSingleFrictionOriginal(
+	btRigidBody& body1,
+	btRigidBody& body2,
+	btManifoldPoint& contactPoint,
+	const btContactSolverInfo& solverInfo);
+
 btScalar resolveSingleFrictionOriginal(
 	btRigidBody& body1,
 	btRigidBody& body2,
@@ -400,6 +406,12 @@ btScalar resolveSingleCollisionCombined(
 	return normalImpulse;
 }
 
+btScalar resolveSingleFrictionEmpty(
+	btRigidBody& body1,
+	btRigidBody& body2,
+	btManifoldPoint& contactPoint,
+	const btContactSolverInfo& solverInfo);
+
 btScalar resolveSingleFrictionEmpty(
 	btRigidBody& body1,
 	btRigidBody& body2,