Fixes for DAs after introduction of 3 LDCs (rather than 1):

Fixes for DAs after introduction of 3 LDCs (rather than 1):

* AliFMDBaseDA: Only write out conditions values for the detector(s)
  seen in the SOD event.
* AliFMDCalibSampleRate: Second (optional) argument of 3 booleans to
  WriteOut.  The array contains the value true of detectors which are
  seen.  Also, specify the std:: namespace explicitly, and use {i,o}stream
  instead of {i,o}fstream.
* AliFMDCalibStripRange:  As above.
* AliFMDPedestalDA:  Write only pedestal upload files for the detectors
  we've seen.
* AliFMDRawReader:  Return argument of 3 bools for detectors seen in
  SOD events.
* Elaborated some documentation