Changes from 24/6/2014

Changelog:
2014.06.24:
- Fixed a bug in "MPEG2IndexFromTransportStream" that was causing it to print out error messages
  (but otherwise work OK) when it saw Transport Packets with "adaptation_field_control" == 2.
  (Thanks to Nadir Raimondo for reporting this.)
- Added an "#ifndef" around the definition of OUR_PROGRAM_NUMBER in MPEG2TransportStreamMultiplexor.cpp,
  to allow it to be defined as a different value.  (Suggestion by Piers Hawksley.)
- Fixed (extremely minor and inconsequential) memory leaks in "MatroskaFile" and "StreamReplicator".
- Changed "UsageEnvironment::reclaim()" to return a Boolean value: True if it was actually
  able to reclaim the object's memory; False otherwise.