pybullet, more robust multi-server connections

Windows shared memory: allow to use custom key.
Improve GUI performance on Windows, submit letters in text as a batch (fewer draw-calls)
quadruped.py: first try to connect to SHARED_MEMORY, if it fails (<0) use GUI
increase Chrome about://tracing json export capacity (press 'p' in Example Browser)
UDP physics server: add --port and --sharedMemoryKey command-line arguments
PhysicsServerExample: add --sharedMemoryKey command-line option (for VR example too)
ExampleBrowser: sleep a few milliseconds if rendering is too fast, use --minUpdateTimeMicroSecs=0 to disable

examples/OpenGLWindow/GLPrimInternalData.h

@@ -13,8 +13,13 @@ struct PrimInternalData
     GLint m_positionAttribute;
     GLint m_textureAttribute;
     GLuint m_vertexBuffer;
-    GLuint m_vertexArrayObject;
+	GLuint m_vertexBuffer2;
+
+	GLuint m_vertexArrayObject;
+	GLuint m_vertexArrayObject2;
+
     GLuint  m_indexBuffer;
+    GLuint  m_indexBuffer2;
     GLuint m_texturehandle;
 };