fixed the following: check the connection in mysql connect; pull the foreign keys only for the selected db; added escape symbols for columns in SQL queries; moved the attribute value selection dialog out of DB Context widget, since this should be the job of the learner.

added --updateuid option to export_package, which assigns uuids to models with no uuids (new widgets, options, etc).

Conflicts:
	workflows/cforange/interaction_views.py