Add command line switch to rename _apid_scope column

[kriswehner]

This column name will vary per-schema of users using the product. This should be as simple as a command line argument to set the column name

[kriswehner]

Initial diff for this is here: https://github.com/seatme/transicator/compare/feature/viper...seatme:feature/configure-scope-column?expand=1

It's stacked behind our viper & rocksdb work, so I'll wait until the pull requests start merging in order to get this up as a pull.

[gbrail]

Taken care of with your patch and the new "-S" flag.