DBI
---
o add method: create_table, gen_ddl

o add method: load_data_dictionary
    - gets attribute definition from data dictionary

o add method: DBI::table

o investigate comparisons in where clauses
    - DateTime, Number

o modify method: DBI::delete should return false when object does not
                 exist -- 0 rows deleted

o fix bug: NULL fields (shmu case) - IS NULL

o add method: update
    Currently, an update does a delete and insert, which was simple
    to implement, but not the fastest for performance.
