Centralize how canned responses are formatted
Add ability to quote original and last messages as a canned response

Add ability to disable canned responses
Fix team drop down selection
Remove priority escalation setting in SLA page (implementation is on todo
        list)

Process inline attachments in thread entry and support inline images in
piped emails

Support inline images across the system, with draft support

Migrate to a single attachment table
    That way we don't need a new table for everything we need to attach an
    inline image to (like a signature, for instance)

Add richtext support for internal notes

Implement images on site pages

* Image paste in Redactor
* Make non-local images optional
* Placeholder for non-local images
* Fix local image download hover
* Don't re-attach inline images

* Change table name from ost_email_filter* to ost_filter*
* Add patch for target field.

But don't send out canned responses for new tickets that matched a filter
with an attached canned response if that response is not enabled. Also,
explicitly block deletes to filters that are in use.

And fix various lint issues, include adding the yet-undefined-but-referenced
deleteAttachment() function for canned-responses and faq entries

Also add a cron job to perform the task on demand
Change the implementation for Ticket::deleteAttachments to call this method
after simply removing all entries from the %ticket_attachment table