Remove accidental inclusion of remote web page

The XKCD index page was accidentally added when testing a new feature for
osTicket-1.8
Support ticket thread items in email templates

* %{ticket.thread.original} represents the original message submitted when
    creating the ticket
* %{ticket.thread.lastmessage} represents the most recent message submitted
    by the end user
Merge pull request #784 from greezybacon/issue/xkcd-oops

Remove accidental inclusion of remote web page

Reviewed-By: Peter Rotich <peter@osticket.com>
Order FAQ by question.
Only strip quoted reply if we have text above the tag
Merge pull request #786 from protich/feature/faq+order

Order FAQ by question

Reviewed-By: Jared Hancock <jared@osticket.com>
Merge pull request #787 from protich/issue/QR

Strip quoted reply revisited

Reviewed-By: Jared Hancock <jared@osticket.com>
Merge pull request #790 from greezybacon/feature/thread-messages-in-template

Support ticket thread items in email templates

Reviewed-By: Peter Rotich <peter@osticket.com>
Fix table name typo
Merge remote branch 'upstream/develop' into develop
Make captcha text case-insensitive
Add --clean option to deploy script

Allows the deploy script to remove files in the target that are not preset
in the current repository. This patch assumes pure stock osTicket
deployments -or- that the files deployed in the target are also present in
the local repository.
Better email headers for In-Reply-To and References

Previously, the References header emitted by the system for new thread
entry auto-responses and alerts included the message-id for which the email
was a reply in the `References` header. This patch corrects the issue by
placing the reply message-id in the In-Reply-To header, and constructs a
correct References header.

That is, if available, the References header received in the email that was
used to create the thread entry is appended to the message-id the email is
actually in reply to. This is the expected usage of the References header.
Disambiguate Reply-To from In-Reply-To mailer opts

Previous the options defined for the Mailer::send() function were confusing
when sending an In-Reply-To header
Merge pull request #823 from protich/issue/captcha-case

Make captcha text case-insensitive

Reviewed-By: Jared Hancock <jared@osticket.com>
Use seemingly-random form input names

Which will help fight off spammers. This should be coupled with logic that
will add some enticing fields, like 'email' and 'name' to invite bot input.
Then, on the form processing side, a spam submission can be detected and
handled differently from human submissions. This should lessen reliance on
CAPTCHA only as spam detection.
Merge pull request #825 from greezybacon/issue/better-email-references

Better email headers for In-Reply-To and References

Reviewed-by: Peter Rotich <peter@osticket.com>
Make cacheable more portable

Move the cacheable code to the Http class and allow the client configuration
to be cached in the browser
In some edge cases, priority may not be set for a ticket

Fixes #40
Allow both internal and required fields

Previously, clients would not be able to create tickets if an internal,
required field existed on any of the forms presented to the user. Instead,
they would be stuck at permanent validation failure because there was no
data for a required field not shown.

This patch adds a feature to the form and dynamicFormEntry objects'
isValid() method to receive a callable to filter which fields' errors should
be added to the form's errors list. This allows for more complex validation
where in some cases, validation errors should not be considered on some
fields.

Fixes #45