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.

Use http::build_query instead of inline urlencode

This patch removes the selection of canned responses as well as the canned
responses navigation page from the ui when the canned responses feature is
disabled.

Since the automatic lock was being acquired but not passed to the autoLock
system, the automatically acquired lock was not being release on away
navigation.

This patch addresses the issue by passing the automatically acquired lock id
to the autoLock system on ticket-view page load and change the ::Init()
method so that the lock id is not cleared with the ::Init() method is called
by the page load.

Compare the database `state` field rather than the admin editable status
name.

Also fix a crash when re-rendering the new ticket by staff page after a
validation error.

Fixes https://github.com/osTicket/osTicket-1.8/issues/1277 and https://github.com/osTicket/osTicket-1.8/issues/1373

Since users can already log in via their email address, offer a friendly
error message when agents configure the user name to be an email address.

Footer should not be in #pjax_container, because the footer is not rendered
for non PJAX requests.

  * Use the title of "Information" with internal tag of "info"
  * Add "Visibility" column to UI and retire "Required" and "Internal"
    columns
  * Add visibility selection to new fields and show visibility to the user
    information fields when displayed on the ticket details form
  * Make the visibility settings translatable
  * Use constants internally for visibility configuration detection
  * Use a larger input when managing the information HTML content
  * Fix validation errors for new fields
    * Enforce new field name uniqueness
    * Enforce new field name character validation

Improve info display & formatting
Only show 8 chars of the last commit

Consider current status settings to determine if a ticket is reopen-able
Show a warning on staff's ticket view if the ticket is not reopen-able

This will allow administrator to indicate if end users are allowed to reopen
tickets in a particular closed status.

This is necessary to avoid confusion vs. closed state.

Also fix crash if the [name] of a widget element started with a digit
character.

This allows fields to specify a visibility constraint that will be evaluated
in real time in the browser to automatically show and hide fields that
should be hidden based on values of other fields in the same form.

Validation is not performed on fields server-side if they are considered
invisible when submitted.

Redirect to tickets listing page when a ticket is resolved or closed via
status change.

Show different messages and placeholder on ticket(s) deletions

Furthermore, revamp the __cdata system to better support multiple selection
fields. Drop the `.._id` fields and use a coalesce of the ID value of the
entry value or the entry value itself. For JSON backed fields, strip some
JSON characters to result in a comma-separated list.

The search engine now uses MySQL FIND_IN_SET to analyze a search selection
in advanced searches. Also, interaction with the MySQL full text search
backend is fully supported.