Merge branch 'master' into cmake

* master: (35 commits)
  add __init__.py file in agents folder
  bump up pybullet version, instruction to visualize agents ppo:
  add TensorFlow Agents PPO training script for various pybullet environments:
  bump up pybullet version
  add minitaur environment randomizer, enable it by default this improves PPO training ( more stable)
  fix compile issue on MSVC
  expose gear erp/relative position target to C-API/pybullet finish much better C++ vrSyncPlugin, running in-the-loop with the physics at high frequency, see also vr_kuka_setup_vrSyncPlugin.py
  return -1 for debugDrawItems in DIRECT mode, instead of failing the API
  bump up shared memory version number add option to recompute forward kinematics, to be consistent with link velocities in pybullet.getLinkState (..., computeForwardKinematics=0/1), thanks to Jeff Bingham for bringing up this inconsistency
  add experimental vrSyncPlugin, that syncs the position/orientation of a vr controller to a gripper (through a constraint) This is in C++ and the sync runs at the simulation speed (240 Hz), so there is less lag than in Python. Modify the pybullet/examples/vr_kuka_setup.py at the end to do this:
  fix a bug in a changeVisualShape/texture selection, out-of-bounds check was using the wrong array. May fix some internal texture mug bug.
  fix a compile error on Windows (variables need to be declared together at the start of a block in C)
  fix compile warnings
  Update b3PluginManager.cpp
  tweak pybullet examples a bit (mac OSX OpenGL runs in mainloop, with python interpreter, so it needs some 'ping' command bump up pybullet to version 1.4.6
  [sharedmemory] Fill-out calculateJacobian command.
  add some missing files for premake, thanks to Jeff Bingham for the report
  add a few more contributors (the list is far from complete though)
  manually apply pull request 457 PR #457 Thanks to aaronmjacobs!
  Update pybullet.c
  ...

# Conflicts:
#	CMakeLists.txt

CMakeLists.txt

@@ -466,7 +466,11 @@ configure_file 	( ${CMAKE_CURRENT_SOURCE_DIR}/BulletConfig.cmake.in
 					${CMAKE_CURRENT_BINARY_DIR}/BulletConfig.cmake
 					@ONLY ESCAPE_QUOTES
 				)
-install ( FILES ${CMAKE_CURRENT_SOURCE_DIR}/UseBullet.cmake
+OPTION(INSTALL_CMAKE_FILES "Install generated CMake files" ON)
+
+IF (INSTALL_CMAKE_FILES)
+	install ( FILES ${CMAKE_CURRENT_SOURCE_DIR}/UseBullet.cmake
 		${CMAKE_CURRENT_BINARY_DIR}/BulletConfig.cmake
 		DESTINATION ${BULLET_CONFIG_CMAKE_PATH}
 	)
+ENDIF (INSTALL_CMAKE_FILES)