* add textured models of ball.vtk (obj/mtl) and torus (obj/mtl) and cloth.

1) allow to render deformables in 'getCameraImage', for TinyRenderer (tested OK) and EGL (untested)
2) allow to have textures for deformables. See deformable_ball.py, deformable_anchor.py and deformable_torus.py for examples
3) deformables: allow to request simulation mesh data (even if there is a render mesh) See deformable_anchor.py for an example usage
   data = p.getMeshData(clothId, -1, flags=p.MESH_DATA_SIMULATION_MESH)
4) fix deletion of deformables, thanks to Fychuyan, https://github.com/bulletphysics/bullet3/pull/3048
5) allow to enable and disable double-sided rendering, p.changeVisualShape(objectUid, linkIndex, flags=p.VISUAL_SHAPE_DOUBLE_SIDED)
6) fix GripperGraspExample, model not found
7) Fix deformable anchor not attaching to multibody with object unique id of 0
8) Fix issue with assignment of unique ids in TinyRenderer/EGL renderer (always use broadphase uid)
9) Avoid crash/issue of simulation with pinned vertices (mass 0) in btDeformableBackwardEulerObjective::applyExplicitForce
10) Store uv/normal in btSoftBody::RenderNode to allow textured meshes
11) (uncomment in btSoftBodyHelpers.cpp): dump vertices and indices in obj wavefront format, when loading a VTK file, for quicker creation of a (textured) surface mesh
12) allow interpolateRenderMesh also for old position-based soft bodies (not only the shiny new FEM deformables)
13) fix a few premake targets
14) update build_visual_studio_vr_pybullet_double_cmake.bat so it suits c:\python37 and installs locally
    for local install of Bullet, see also this example https://github.com/erwincoumans/hello_bullet_cmake

examples/MultiThreading/main.cpp

@@ -46,7 +46,7 @@ SamplelsMemoryReleaseFunc,
 
 b3ThreadSupportInterface* createThreadSupport(int numThreads)
 {
-	b3Win32ThreadSupport::Win32ThreadConstructionInfo threadConstructionInfo("testThreads", SampleThreadFunc, SamplelsMemoryFunc, numThreads);
+	b3Win32ThreadSupport::Win32ThreadConstructionInfo threadConstructionInfo("testThreads", SampleThreadFunc, SamplelsMemoryFunc, SamplelsMemoryReleaseFunc, numThreads);
 	b3Win32ThreadSupport* threadSupport = new b3Win32ThreadSupport(threadConstructionInfo);
 	return threadSupport;
 }