This will allow for any threadable object to render the thread.

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

Add a tab for tasks
Add mass action for tasks

Also add resend only option (for the case when "Edit and Resend" is not
allowed).

Add in the ability for an agent to resend a response. Optionally editing the
response before sending it, and setting the signature as is possible with
the usual responses.

When the response is resent, the edited version is marked as GUARDED, and
subsequent edits will result in new links in the history chain. That is,
when a response is edited and resent by an agent, that response will remain
in the history chain.

The new role would like be assigned to power users and would all such users
access to edit any post by any user.

Agents can always edit their own posts, and department managers can edit all
posts while the ticket is in the department they manage.

Threads can be edited by marking the original as hidden and setting it's PID to
the id of the new entry. The new entry has cloned data from the original and
sets the `updated` timestamp to reflect the time of last edit. An edited flag
is added to the new entry to reflect its origin.

This patch suggests that agents can edit their own posts, department managers
can edit posts while the ticket is in their department, and that help desk
admins can edit anything.

If a post is edited more than once, only the most recent edit is kept.

Fixes #1854

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.

Follow-up PR to the comment here:
https://github.com/osTicket/osTicket-1.8/commit/06d3a0f3e2a4557ca72faa916859b9315635dfe4

Fixes #1926

add __() function for not translated words.

This patch adds an error to the page if unable to configure the archive
folder and POP was selected as the mailbox protocol. Generally, POP servers
do not support anything but the INBOX

Unassign tickets on transfer when the target department has assignment
restriction and the assigned staff is not a member.

Disable claim (quick self-assignment) when above restriction is in effect.