Task #10045: Allow a subset of the antenna fields to be used for beam-forming. The delays  are not filtered, that is, are computed for all TABs and stations.

  Most changes are renaming. 'Station' idents are unclear wrt expect values "CS001" vs "CS001HBA0".
    Parset.cc has a clear "translation" point. Added 2 TODOs, as renaming these two functions is too invasive for this task.
  Add option to restrict cobalt nodes to those that receive streams from ant fields in the obs.
    Default off, because as JD mentioned, this may exclude nodes that are needed for computing only.

Task #5555: Compute delays in caller's thread, simplifying the code. Caller is a light-weight thread already (GPUProc/Station/StationInput::StationMetaData)

Task #4691: Support bf TAB absoluteAngle keys. The old relative angle keys will be used if the new ones don't exist (backwards compat). Test parsets not yet updated.

Task #5105: Removed superfluous read/write functions for Delays (we send them through SubbandMetaData these days)

Task #4716: BIG change. 1. Pulled ScopedLock out of Guarded_MPI_* stack to merge lock+unlock sequences. 2. Expanded SampleBuffer sync to have a reader per beamlet. 3. Fixed StationInput not to mix up subbands and meta data between receivers. 4. Align rtcp SampleBuffer sizes with Cobalt.blockSize. 5. MPISendStation now sends to ONE receiver. 6. Delays can now be requested for a subset of the subbands. 7. Release all readers using noMoreRead() when locking a block, before calling startRead on any of them, to prevent a deadlock with the writer.

Task #3696: Fixed 'false positive' out-of-bounds error in reading/writing of BeamDelays in Delays.cc

Task #4449: Test conversion engine immediately, and give useful hint for most common error (not having measures data installed)