Update: TMS interface can now supplies unsupplied default values

The TMS table creation interface required us to supply default
values for fields of types other than Unicode. Now, the default
value field can be left blank and the TMS view script will supply
the following default values: False for booleans, 0 for integers,
and 0.0 for floats.

This needed a fix in TMSModels, specifically in
TMSRecord.make_record's way of assigning an attribute based on the
unicode value that is saved in the TMS database.