AMORE & QA fixes.

AMORE & QA fixes.

  - AliMUONQAChecker prevent the method AliMUONQAChecker::CheckRaws to return a NULL pointer if a
     TrackerData object is not present in the first specie (kDefault). Now it returns
     NULL only if there no TrackerData object at all.

  - AliMUONCalibrationData : add a bypass to force the usage of some external calibration data (for AMORE)

  - AliMUONTrackerDataWrapper : remove an uneeded method

(Guillaume)

  - AliMUONQADataMakerRec : introducing the beautifier for presenting a nicer Raw Data QA to the shifter.
    This is just a first approach, as most of that should probably be done in the Checker on the longer term (to be discussed...)

  - AliMUONDigitCalibrator & AliMUONTrackerDataMaker : do not force the number of sigma to cut on the charge. Should be taken from the recoparam.
     This was impacting the QA only (forcing it to use a 3 sigma cut, where anywhere else we use 4 sigma cut).

(Laurent)