[lmi] Fate of DB_DynamicMandE and DB_DynamicSepAcctLoad

[Greg Chicares]

Should these two database entities be expunged, as was the kindred
DB_DynamicCOI? They enable or disable tiering and banding.

Advantage: if you ever want to disable tiering and banding, these
settings are easy to manipulate; but probably you never want that.

Disadvantage: if you forget to set them the right way, surprise!

I'm about to sentence them to expunction. Please let me know if
you object. The sentence won't necessary be carried out soon.

DB_DynamicMandE won't be easy to kill. It causes the last month's
M&E rate to be stored in the ledger. Probably it would be better
to store an average if the rate varies by month. But the program
ought to be able to figure out when to do that. Averaging isn't
a concern for the other two AFAICT: they're dollar amounts that
it seems appropriate to sum.