Thread-able objects (e.g Ticket) can extend the class to add object specific
util routines.

Auto-close toop tip box when element goes away

Generalize how we show object/data preview. The url to get the preview is
now based on data-preview attribute on the element in question.

The size of the dialog can be auto-adjusted based on the options

Add support for complex options to support complex field rendering.

Validate all fields with data even if it's for presentation only

Use generic attachment table for all attachments system-wide.
Drop thread entry attachment table

Detach conversation thread from ticket to make it more generic. Any object
can now have its own thread complete with entry type and attachments.

Use generic attachment table for all attachments system-wide.
Drop thread entry attachment table

Detach conversation thread from ticket to make it more generic. Any object
can now have its own thread complete with entry type and attachments.

The commit also renames some fields in department table.

Adds migration patch for role-based access

Introduce the concept of role-based access for agents.

The commit also renames some fields in department table.

Slight rework of Role feature