Add options to allow better control of 'cv ttype_populate'

 - Break monolithic cvv_ttype_populate code down into smaller pieces
 - New options --dryrun/-n, --limit N/-l N
 - Handle option/argument mutual exclusion
 - Handle cases where files don't have media info (eg., 0 length)
 - Report the number of records processed and skipped

Change-Id: I84176f9c2165b968c3757c002573660c1b08609d