deleted products should not be available?

Fixes #4362
Fixes #4437
use authenticated url for option_type_autocomplete

option_type autocomplete wasn't using the authenticated url helper.  Updated to mirror how taxon_autocomplete
works.

Fixes #4368
Fix Product#possible_promotions to use promotion_id, not activator_Id

Fixes #4395 an error on the product show page

Product#possible_promotions is to use `:promotion_id` instead `:activator_id` - because `activator_id` was renamed to `promotion_id`

Fixes #4416
Make Promotion#expired? always return true/false rather than true/false/nil
Remove oj dependency due to #4431

Fixes #4431