Make custom field column label clickable.
Save custom field columns with the rest.
Use custom field ID instead of name.
Display custom field data on ticket listing page.
Added default ticket type select to new project / project settings forms.
Updated install and upgrade files to add default ticket type ID column to projects table.
Add `default_ticket_type_id` property to the `Project` model.
Save the default ticket type ID when updating a project.
Added translation string for "Default ticket type".
Save default ticket type when creating projects.