Changes from S. Rossegger :

Changes from S. Rossegger :
1. Many fixes to comply with the AliRoot coding conventions
2. Improvement in "lowest pt tracked" -> now uses helix parametrization for calc. of a,b
3. Added a more sophisticaed efficiency calculation which includes the possibility to make chi2 cuts via Confidence Levels (method of Ruben Shahoyan) plus adding 'basic' detection efficiencies per layer
4.  Adding "ITS Stand alone" tracking capabilities via forward+backward tracking -> Kalman smoothing is then used for the parameter estimates (important for efficiencies)