The MDS is now populated using a lazy scheme - like a cache, items not present are added. Add a BES command so that a client can connect to the BES and tell it to add DDS/DMR info about item 'X' without a specific DAP request for that item. We can then modify bescmdln to implement a simple command line tool to pre-populate the MDS.
This could be implemented as a shell script.
This should also add the DMR++ when that's applicable.
When we populate a DMR++, put all the responses there.