various jdbc import issues

We should not through an exception if the primary key for a foreign key cannot be found - which is most likely due to being filtered from import, instead the key should just be dropped.

We should automatically remap the invalid column name char '.' to '_' - since this is the current behavior of designer.

We also do not have good handling for the mysql bit type, which can be larger than a single bit.

Default values should be captured and should be normalized for BIT types.