Add V-REP agent and experiment.

[rezama]

To run the V-REP agent:

1. Download V-REP.

http://www.coppeliarobotics.com/downloads.html

2. The V-REP agent communicates with V-REP using its remote API:

http://www.coppeliarobotics.com/helpFiles/en/remoteApiOverview.htm
http://www.coppeliarobotics.com/helpFiles/en/remoteApiClientSide.htm

Help Python find the vrep module:

$ export PYTHONPATH=$PYTHONPATH:path/to/vrep/programming/remoteApiBindings/python/python

Copy the file remoteApi.so (or remoteApi.dll, or remoteApi.dylib) from
the V-REP installation folder to the root folder of your GPS installation:

$ cp path/to/vrep/programming/remoteApiBindings/lib/lib/64Bit/remoteApi.so path/to/gps/

3. Launch V-REP. Leave it open prior to running the experiment. The
   agent automatically loads and runs V-REP simulations as needed.

4. Run the experiment:

$ python python/gps/gps_main.py vrep_example

[dujinyu]

hello, I'am very interested in your contribution. but i met some problems.
I have tried your code, but when i try new robot model, such as ur5, it doesn't work.
i created a new scene where a ur5 robot try to reach a given fixed point. the robot doesn't work well. when the simulation started, the ur5 collapsed tp the ground quickly, and it seems that it is influenced by gravity. i'm very confused about it.
are there any precautions when i use vrep with torque/force mode and use sim.setJointForce.