New class hierarchy

[grzanka]

Current class hierarchy comes from analysis of proton beams. I think we can easily get rid of some of the classes and move some of them (i.e. LateralProfile, DistalProfile) to user code: examples etc...
We need a clear separation of responsibilty between various classes. At the beginning I would start with two:

1. Curve - general class to represent set of (x,y) pairs where x coordinates is in ascending order
2. Profile - subclass of Curve, for which y coordinates are first more-less increase and them more-less descrease
   For Profile it might sense to calculate width, fwhm and other features based on rising-falling character, which for Curve - not.