The detection of inline images in the mail processor causes inline images to
be removed from the attachment list, if listed there. However, the
attachments in the attachment list were not keyed by the attachment-id, so
there was no proper way to detect and remove the attachments from the list.

This patch properly keys the attachment list by the attachment file_id

Change recent activity date as opposed to create date on ticket view

Fix duplicate phone number (again)

- Tickets will recent replies from the user floats to the top.
- Priority still tops the effective

  * Require a label on form fields
  * Require variable name to be unique per form
  * Fixup duplicate phone numbers on upgrade

This include URLs in embedded links as well as URLs for external images and
videos embedded via iframe elements.

Also add images on pages to the drop-down list for image choosing, and fix
display of images on the client portal.

Fixes #138

Allows the client to be changed on a ticket. Previously, only the
information about the client associated with the ticket was editable. This
patch permits assigning a completely different user to the ticket.

Fixes a case where multiple tickets are created in one request (such as a
cron job triggering multiple email fetches). The TicketForm::getInstance()
called in Ticket::create() used a singleton pattern to retrieve a cached
instance of the TicketForm. In the case of ticket creation, each ticket
needs a new TicketForm entry instance.

  * Upgrade to Redactor 9.1.7
  * Use a (x) icon from font-awesome for the dialog

Ultimately, in the user information ("contact information") form, forbid
updating a user's email address to an email address in use by another user.
Because email addresses are a unique identifier of user accounts, they
cannot be reused between different users.

Fixes #126

Before, the draft was only cleaned up when progress on the ticket was
tracked with the reply box.

Validation errors in user form were not displayed on the interface

Fixes #111

If an email arrives in the system without a "personal" field (name), the
email address is used as the name. The email address, however, is not parsed
well by the PersonsName constructor. This patch uses the mailbox of the
email address as the name.

Also include a slight boost to the mbstring compatibility functions declared
in the bootstrap::i18n_prep() function