improved for inserting profile timings from Python, to analyzer performance of pybullet programs.

See examples/pybullet/examples/profileTiming.py for an example. Note that python and c++ is properly interleaved.
Open a timings with a name, close the timing without a name. Note that timings can be recursive, added/popped as a stack.

examples/pybullet/examples/profileTiming.py

@@ -1,11 +1,18 @@
 import pybullet as p
 import time
-
+#you can visualize the timings using Google Chrome, visit about://tracing 
+#and load the json file
 p.connect(p.GUI)
 
-t = time.time() + 0.1
+t = time.time() + 3.1
 
-logId = p.startStateLogging(p.STATE_LOGGING_PROFILE_TIMINGS, "haha")
+logId = p.startStateLogging(p.STATE_LOGGING_PROFILE_TIMINGS, "chrome_about_tracing.json")
 while (time.time() < t):
   p.submitProfileTiming("pythontest")
+  time.sleep(1./240.)
+  p.submitProfileTiming("nested")
+  time.sleep(1./1000.)
+  p.submitProfileTiming()
+  p.submitProfileTiming()
+
 p.stopStateLogging(logId)