model.

Previously, the subject was duplicated, which is really confusing

And avoid double encoding email bodies if html thread is not enabled

Use a PHP setup which uses the built-in PHP tokenizer to parse and traverse
PHP scripts to determine (possible) access to uninitialized variables

Allow for type and encoding specification of the message body and better
describe the integration with custom form fields.

*This is a major redesign / rework of the osTicket base*

This patch drops the concept of static ticket metadata and allows for an
admin-configurable arbitrary data that is attachable to tickets

The system is architected such that the base osTicket install now comes with
a "default" form that has fields for subject, name, email, and phone number.
This form is editable to allow for the addition of arbitrary other fields;
however, the basic fields must remain in order to be associated with a
help-topic and attached to a ticket.

This concept can be expanded to allow for arbitrary data associated with
registered clients or ticket thread items.

Forms are comprised of sections. Sections have a title and instructions
properties and a list of fields. Fields have various implementations to
represent different data such as text, long answer, phone number, datetime,
yes/no, and selections, and are configurable to define the look and feel and
interpretation of the respective form field.

Dropdown lists are represented as "Dynamic Lists", which are
admin-configurable lists of items. Dropdowns can be optionally represented
as Bootstrap typeahead fields.

This also adds the start of a simple ORM which will hopefully be expanded in
the future to support multiple database platforms. Currently, only MySQL is
implemented.

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

This patch affords an administrator the ability to remove the
[#%{ticket.number}] from the email template subject line for the new ticket
autoresponse and the new message autoresponse. Previously, the ticket number
with a prefixed hash in brackets was used to identify which ticket thread an
email was in reference to.

With this patch, the email message-id (which was already kept on file) is
sent in the MIME "References" header. When a user responds to and
autoresponse email, the "References" will include this message-id in the
return email. The ticket thread is then matched up with the email based on
the message-id rather than the subject line.

Ticket numbers are still supported in the subject line, in the event that
non-compliant email clients do not properly include the References header.

Previously, the @ext attribute for the phone number field was assumed to be
included. An XML payload without the @ext attribute would have been
corrupted to include only the first digit of the phone number, which would
fail validation.

This patch correctly handles the XML payload without the @ext attribute for
the phone number. Subsequently, the <phone_ext> element is now also valid
(and optional as well).

Fixes #670

Incoming messages with empty body and an inline attachment might not have
parts - depending on encoding used.

* Use "-" tag for emails with empty body/message

Change /api/task/* -> /api/tasks/*

Remove piping setting option - it's now part of ticket create service (which include XML & JSON)

Implement remote cron as api task (more to come)

Log ALL API errors along with API Key used

    * Don't require a content-type, so data:,this is content
      is perfectly allowable. Such content is assumed text/plain
    * Support the charset hint, so
      data:text/plain;charset=iso-8859-1,content here
      will be translated to UTF-8 if the php iconv() function exists.
      Otherwise, content is left intact and assumed by the database to by
      UTF-8 already