* Enhancement: Add Job Types to the My Alerts table.
* Enhancement: Use multiselect UI for Job Types in the form.
* Fix: Job Type field missing in the form.
* Fix: Alert message displaying on `[job_alerts]` shortcode.
* Dev: Move the `[job_alerts]` sign-in message to a separate template file.
* Add unsubscribe link to the email and text explaining why they are receiving it.
* Add email permission checkbox.
* Fix job type form showing up when job types are disabled by adding taxonomy check.
* Don't encode html special chars for email output.
* Remove job alert posts when removing user.
