When computing the column names to use for insert/update methods on dao instance consider the class's column-map and not just the slots' names.
When building up s-sql forms in the dao readers/writers make sure to use :raw for the column names (which we have as strings and not symbols)
Make sure to compute the right sql column name for the :returning columns in insert-dao
Tests for :col-name DAO slot argument.
Add failing test showing database error raised when attempting to write empty arrays.
Fix empty array problem by using Postgres's array literal syntax for empty arrays