Bug 20917

The ILL module has the ability to send emails containing details of requests to "partner" libraries. This functionality, though currently in the core ILL code, is actually only required by the "FreeForm" backend. It is surfaced in the UI as a form containing an email template and a multi-select to select the partners who will receive the email.

The email functionality offered by ILL, though functional, is lacking in some important respects, which this bug proposes addressing. Proposed enhancements, which are all inter-related, are:

- Move emailing functionality from the core ILL module to the FreeForm backend where it is actually used
- Email is sent independently of the Koha message queue, which is understood to be undesirable, this should be addressed
- As such, there is no ability for users to specify a default message template, using the Notices and Slips module, this should be addressed
- It is not possible for users to specify default "reply-to" addresses for all ILL related emails, currently the ReplyToDefault syspref is used, this should be addressed
- No message notification is sent to nominated staff when a request is modified, this should be addressed