This test case verifies whether get_table returns the most up-to-date
table object containing all columns that has been added to the table
since the last cache update.
The problem occurs in the following scenario:
* an instance of a Table, obtained through Database.get_table, is used
to insert some data
* a different instance of Table, obtained through Database.get_table
call after the data has been inserted, uses a Table instance that is
not up-to-date
The result is that, e.g. the keys created with the first Table object
aren't accessible via the second object.
This fixes the problem by updating the table cache in
Database.update_table.
Grzegorz Niewisiewicz