Add department setting to limit ticket assignment within department to
department members only. This is necessary for departments with strict
policy on who can access tickets.

The setting doesn't limit team assignment or auto-assignment via help topics
and ticket filters.

Some emails providers (e.g gmail/google) won't deliver emails marked
bulk/autoreply to group email address.

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

Drop old mcrypt class

Spelling, grammar and readability in upgrader documents
  - Tweaked spelling, grammar and wording to make the text of the upgrader
    pages more readable.
Fixed spelling regression
  - Higly —> Highly
Spelling and readability fixes for /include/class.* files
  - Fixed some spelling mistakes
A couple more spelling/readability fixes.
  - More fixes