Important bug fixes for QA trains.

Important bug fixes for QA trains.
Should be ported to the release ASAP.

* AddTaskForwardQA.C:  Set the cuts properly.  They where
  previously changed to do a quick'n'dirty hack for the QA
  to work in case we had no correction objects.  This case
  is now fixed in AliForwardQATask.cxx directly instead and
  is more robust.
* ForwardAODConfig.C: Clean-up in cuts code (not values)
* trains/MakeQATrain.C: Fix to work with new TrainSetup
* AliFMDDensityCalculator.cxx: Remove superflous warning
* AliFMDEnergyFitter.cxx: Remove superflous debug and
  important warning
* AliForwardQATask.cxx AliForwardQATask.h:
  - Protection against missing correction objects by
    setting hard-coded values for cuts
  - Proper call to AliFMDDensityCalculator::Calculate
  - Fix bug that caused energy loss fit results where
    lost.
* Some fixes for QA shell script