Don't show fields disabled by help topic
Pass create mode for pre-selected help topic forms

This commit addresses inconsistencies on how field edit rights and
visibility are are handled.

- Create a new database patch to add a new Event table, use event_id instead of state for thread_events, and remote the 'state' column in thread_events
- Create the Event class
- Use event_id instead of state for Thread Events

This addresses an issue where the client portal shows Featured FAQs on the
sidebar even thought the Knowledgebase is Disabled.

This addresses an issue where the client side thread entries are all grouped
within the same div. This pushes all grouped entries to one side of the page
making them illegible.

This means Agents can no longer choose to add a BCC User while creating or responding to a Ticket.

This also means that if a User emails in a Ticket where someone is BCC'd, the Ticket will be created without the BCC'd User(s).

If an email is sent where the Department email is BCC'd, a Ticket is created for that Department and other Users in the email are added as Collaborators.

This also changes the response options for Agents. They now have the options to:
- Reply All (User + Collaborators)
- Reply to User (only the User)
- Do not Email Reply

(Previously the options were Reply All, Reply to User, Reply to CC + User, Reply to BCC, Do not Email Reply)

Commit c4579277 introduced an extra administrative security feature to
restrict files access to signed in users only, even  if a user has a valid
& signed download URL. The feature, however, did not take into account
public images & files associated with FAQs and pages such as
landing/thank-you pages.

This commit addresses the shortcoming by adding a reference ID (attachment ID)
to the download/access URL, that can be used to deduce the model/object type
that the file request is associated with. The technique will allow us in the
future to enforce ACL at the file level depending on privacy settings and
the security clearance of the user (agent).

This pull request addresses issues 2955 & 3524 where an Agent's name is
visible to User even when Agent Identity Masking is enabled. This adds a
check for `hide_staff_name` in the config table and if enabled the system
will show Staff on all thread responses and events.

This partially reverts a change in the ORM changing the QuerySet::all()
method to return an Iterator rather than an array. I spent a while proposing
a patch to replace usage of all() with iterations; however, I cannot propose
a valid reason to abandon the previous methodology.

This reintroduces the previous behavior: calling all() will yield an array
of results from the QuerySet's iteration system.

Add a global option to disable avatars on thread correspondence . Agent's
and user's profiles will still show an avatars.

Add preference to agent's profile to enable relative time use.

So, fields with only the 'required' flag set for users are shown for the
registration page.

Fixes #2364

Initially, include support only for Gravatar

This adds the concept of independent multi-thread rendering

Credit: Jared

* Fix crash in Ticket::getLastRespondent
* Fix crash is ORM if using a superclass of a relationship from cache. For
  instance, if the cache contains an ObjectThread instance, but a
  TicketThread instance is required in the relationship. In such a case, use
  the cached data, but change this class. This; however, violates the single
  nature of cache entries.
* Fix spurious events appearing after upgrade due to deleted tickets
* Ensure floating content in thread-body divs does not float past the bottom
* Provide an anchor to thread entries
* Show thread entries before events where both have the same timestamp
* Fix double events for collaborator additions
* Credit email sender with collaborator addition
* Fix incorrect rendering of collaborator addition event
* Fix crash on new ticket due to non-static function
* Fix missing sort on sub-query if explicitly declared in QuerySet
* Fix missing parentheses in SQL for ['field__eq' => QuerySet]
* Fix incorrect SQL on compileSelect for models with inherited $meta['table']
* Dynamically adjust relative time client side

This patch (which needs further development), introduces an extra field to
the %attachment table to store a file's name, in the event that two files
with the same content are stored in the database with differing names. In
such a case, the name is stored in the %attachment table. This allows the
attachment to specify a different name each time the same file is attached
to something in the system.

Also log client edits as an event

Also, show sidebar on "Other Resources" pages, and fix a problem displaying
the correct Other Resource page.

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

And properly escape and display form title and instructions

Add support for complex options to support complex field rendering.

oops: Fix crash upgrading to c7c82835

oops: Fix crash rendering ticket view

oops: Fix crash posting response to ticket

oops: Fix refresh url after ticket reply post

orm: Locate annotations after the root model's fields

orm: Add PK field check for DISTINCT aggregate expressions

When using the DISTINCT option for aggregate expressions, ensure that when a
relationship is used in the aggregate, that a single field of the remote
model's primary key is used — rather than the foreign key, since it would
never have more than one unique value.

search: Re-implement basic ticket search

oops: Couple trivial changes

oops: Fix date formatting for PDF output

oops: Fix staff profile view and update

oops: Fix canned response listing

orm: Fix crash compiling WHERE IN (nested select)

nav: Move settings/email to email/settings

i18n: Make field visibility config translatable

oops: Fix crash adding field to custom form

forms: Fix `required` flag transfer to FormField

oops: Fix bad merge on new ticket by staff

forms: Show uneditable fields on new ticket by staff

oops: Fix bad merge on client ticket view

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.

In-line forms are forms that are rendered as one field. The data of the
inline form is also saved in the data for one field. Currently, the data is
rendered to JSON and stashed in the database.

The data in the field is also accessible via the variable replacement
system, so something line %{ticket.field.subfield} can be handled by the
inline form field.