Update Main.cpp

Update to use the general factory
merge with cristian branch
Merge pull request #4 from jcliberatol/origin/merge

merge with cristian branch
fixed merge after merge with the merge branch and origin/merge branch
Added the new emestimator class for the strategy construction in the
merge, separated the Estep
added step M
Successfully separated Estep and MStep in a new inherited class
Added the initial values in the new strategy pattern
added support for parameter transforms in the emestimators and added
EM3PL transforms
Finished te EMEstimation independence of models.
Added print capability in models for printing and reporting of the
estimated parameters
Finished the merge
Merge pull request #5 from jcliberatol/merge

Full merge with 2pl complete, able to start merge with 1pl and 2plconstant a.