Add model validity check for folding models.(soloved issue #6)

  I have added a new model validity check after each optimalization step when new model is created from optimalized parameters.
  It controles if newly created model has the same count of verticies as the old one. If not than new model is invalid.
Add realitime images reading from Kinnect.

I have created new subscriber/server that reads data published by Kinect and offer last read image as an service.
  - ImageReaderService.py
It means to create new service message.
  - srv/GetImage.srv
Moddify Folding process script to use the service.