Required schema changes

Input and output settings are stored in serialized fields. But serialize could cause storing of \00 chars so better to prevent this bugs in future.

Also using NOT NULL for fields without default value is wrong and leads to unavailability to save preset with error

user warning: Field 'input_data' doesn't have a default value query: INSERT INTO galleryapi_presets (name, input_name, output_name) VALUES ('test preset', 'cckimagefield', 'djembegallery') in /var/local/drupal-6.17/includes/common.inc on line 3477.

Also preset name should be unique to allow modules like features to export presets.

This patch changes schema and provides hook_update_N() for this changes