This is an enhanced version of the sluggable template, it adds a few options:

unique: true (The default) Generates a unique slug by adding incremental -xxx at the end uniqueBy: [field1, field2...] Generates a unique slug but allow the same slug when field1, field2 are the same uniqueIndex: true (The default) Generates a unique index in the table for the slug (The index is based on the field of the name option, plus the uniqueBy fields)

- Also when the option fields is empty and a method named getUniqueSlug exits in the model, it is used to generate the slug.

- Also works to make the slug unique when it is set manually or updated by a user.

The test case joined has 27 tests that pass.