Add preliminary PhysX 4.0 backend for PyBullet

Add inverse dynamics / mass matrix code from DeepMimic, thanks to Xue Bin (Jason) Peng
Add example how to use stable PD control for humanoid with spherical joints (see humanoidMotionCapture.py)
Fix related to TinyRenderer object transforms not updating when using collision filtering

examples/SharedMemory/plugins/stablePDPlugin/Rand.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <random>
+
+class cRand
+{
+public:
+	cRand();
+	cRand(unsigned long int seed);
+	virtual ~cRand();
+
+	virtual double RandDouble();
+	virtual double RandDouble(double min, double max);
+	virtual double RandDoubleExp(double lambda);
+	virtual double RandDoubleNorm(double mean, double stdev);
+	virtual int RandInt();
+	virtual int RandInt(int min, int max);
+	virtual int RandUint();
+	virtual int RandUint(unsigned int min, unsigned int max);
+	virtual int RandIntExclude(int min, int max, int exc);
+	virtual void Seed(unsigned long int seed);
+	virtual int RandSign();
+	virtual bool FlipCoin(double p = 0.5);
+
+private:
+	std::default_random_engine mRandGen;
+	std::uniform_real_distribution<double> mRandDoubleDist;
+	std::normal_distribution<double> mRandDoubleDistNorm;
+	std::uniform_int_distribution<int> mRandIntDist;
+	std::uniform_int_distribution<unsigned int> mRandUintDist;
+};