Update in HP decoders:

Update in HP decoders:

Added:
A new high performance decoder for the MUON trigger detector (AliMUONTriggerDDLDecoder).
The corresponding stream interface class AliMUONRawStreamTriggerHP has been created
to interface the decoder with AliRoot.
Also added the abstract class AliMUONVRawStreamTrigger and made both AliMUONRawStreamTrigger
and AliMUONRawStreamTriggerHP inherit from that. This allows easy exchange of the decoders.

Bug fix:
AliMUONRawStreamTrackerHP was not working for mixtures of empty events and partial events. This is now fixed.

Minor changes:
Made some documentation corrections to AliMUONRawStreamTrackerHP.
Also added static methods to the AliMUONTrackerDDLDecoder to be able to read out the raw data structure key constants from other classes, similarly to what is now done in AliMUONTriggerDDLDecoder.

(Artur)