Alexander Ziegler / gammalib

The coding and design conventions (CDC) document was also updated.

Initially, there was a unlogic relation between GModels and GOptimizerPars, where GModels derives from GOptimizerPars, but both classes contained different types of objects. GModels is a model container, while GOptimizerPars is a parameter container.

Now, GModels derives directly from GContainer and no longer from GOptimizerPars. The GModels::pars() method has been added to extract a flat array of model parameter pointers into a GOptimizerPars object.

GOptimizerPars, which was abstract before, is now a real container class that also derives from GContainer.

For some reason, the GOptimizerPars class was not abstract although it should be an abstract class. The code has been modified to make the class now abstract.

All classes now derive from GBase. ostream and GLog friends are removed since they are now implement at the GBase level.

…td::vector<GModelPar*> instead of GModelPar**; add print() method and GLog friend