[Halld-offline] BCAL Geometry updated in HDDS

[David Lawrence]

Hi All,

   This morning I committed an update to the BCAL geometry definition in 
HDDS to bring it into alignment with the Engineering Drawings. The net 
effect is that the BCAL was moved out radially about 7.4mm.

   There was also a tightening of a couple of "envelope" volumes that 
were extending further in towards the beamline than needed. These were 
apparently masking off some FDC cables. The material contribution was 
small and just in front of the BCAL so would have had little effect. 
This is corrected in the current geometry nonetheless.

   Thanks to Simon for initially pointing out the issue with geometry to me.

   To get these changes, you will need to update to the latest version 
of HDDS in the trunk.

Regards,
-David