Add internal forms for generic object assignment and transfer. This provides
for a consistent action forms across the system.

Add ability to mass set errors

Add ability to extend Form
Support the concept of form ID
Clear/hide field errors on blur

This feature addresses a major issue with the initial implementation of the
custom data system. The original system confused the usage of
database-backed field (dynamic-fields) and their corresponding
implementation. This created the need to crate awkward caching pieces to
ensure that validation errors and data was maintained. Furthermore, the
system confused the linking between form instances (dynamic-entry) and the
form used to represent that entry.

This patch addresses the confusion in two ways:

Dynamic form entries do not link directly to the dynamic form. Instead, the
::getForm() method returns something from the forms API directly.
Furthermore, the ::getFields() method does not return dynamic field
instances (database backed / designed fields). Instead, the actual
implementation of the fields from the forms API is retrieved. This allows
the fields to *always* be cached, which helps preserve data and validation
state.

Secondly, the dynamic form uses the same system, so that requests to turn a
dynamic form into a form (via ::getForm) will also result in the same
behavior, again, where the fields are represented as forms API fields rather
than the dynamic fields.

So going forward, the dynamic fields are *only* used to create corresponding
forms API field implementations. The are associated with the dynamic
counterparts as sparingly as possible.

Support using value or abbrv. for choice/selection input fields.

Reset field content when building a new form

Get all dynamic fields in DynamicFormEntry, not just fields with answers

This partially reverts commit bff191b6.
The hasSpecialSearch() method can be retired in `develop-next` — NOT in the
`develop` branch

Add a text box widget to selection field. It functions like typeahead and
drop down widgets with the exception that the user doesn't get the hint. This will
be useful when a list needs to be used to validate user's input.

This allows for multiple priority fields to specify differing defaults, and
it also allows for a selection of 'System Default' in the config, which
renders as 'Default' when rendered.

It also fixes up a couple PHP warnings about include/class.forms.php

If the ticket details form has an extra field of type "Priority Level"
(beyond the one built in), exports of tickets will be empty.

This patch addresses the issue in the exporter which uses an older version
of the custom data materialized view (__cdata table), which created separate
columns for selection and ID values. The current cdata system only creates a
single column and stores the ID value. It also addresses an issue where the
ID column was passed to the PriorityField::to_php() as the first argument.

This patch converts the central file and threading classes over to use the
ORM.

This script adds a single download script, 'file.php', which provides access
to files of all types to all users. It uses a HMAC signature system with an
expires time, which allows signed URLs to be sent to external users.

This also fixes an issue with the Http::cacheable() method, where the
last-modified and Etag headers were not properly compared, which resulted in
permanent cache misses by the client.

Ensure that when generating the list of acceptable file extensions, that the list is lower cased, because the extension from the filename will be lower-cased before attempting to find the extension in the list of acceptable extensions.

Add ability to add tasks to tickets.

Introduce the concept of tasks. Tasks are to do list that can be attached to
any object e.g Ticket.

Add support for complex options to support complex field rendering.

Validate all fields with data even if it's for presentation only

Conflicts:

	include/i18n/en_US/form.yaml
	include/staff/templates/dynamic-field-config.tmpl.php
	include/staff/ticket-view.inc.php
	include/staff/tickets.inc.php
	scp/js/scp.js

This will be used for greater flexibility in visibility and requirement
settings.

Allow fields to be configured for view / edit / required for both agents and
end users. Fields can also be disabled now so that the field remains in the
form but is no longer displayed for new entries.

Allow tickets to be created without a subject — use the help topic full name
instead.

This is necessary so we can consolidate various settings and permissions
into one bit mask field.