- Implementing the possibility to histogram the raw adc values when reading

- Implementing the possibility to histogram the raw adc values when reading
  raw data.
- General speed improvement
- Corrected a bug (using a 2DMap where a 1DMap was needed) that lead to very
  poor data reading performance.
- Added new class AliMUONSparseHisto to hold adc values in the most compact
  way possible (used later on by AliMUONTrackerData to generate TH1 histograms)
- Moved generation of calibrated data to its own class
  AliMUONTrackerCalibratedDataMaker, in order not to slow
  down the plain raw data reading (made in AliMUONTrackerRawDataMaker)
(Laurent)