Fix parsing issue in strtotime()

Reviewed-By: Peter Rotich <peter@osticket.com>

PHP can't discern the difference between d/m/Y and m/d/Y when just the date
is submitted to strtotime(). Unfortunately, strptime() is not available
until PHP 5.1.0. This patch forces datepickers to change their values to
YYYY-MM-DD upon submission to disambiguate parsing issues.

Fixes #832

And freshen up the upgrading guide

Add long lost kb category listing background

Reviewed-By: Peter Rotich <peter@osticket.com>

Use system date format for date picker

Reviewed-By: Peter Rotich <peter@osticket.com>

Previously the American date format (m/d/Y) was used exclusively for
formatting dates in the datepicker widget. This patch enables the widget to
be formatted based on the format set in the admin panel.

Fixes #829

Content disposition parameters are optional

Reviewed-By: Peter Rotich <peter@osticket.com>

If a Content-Disposition header exists for an attachments, it isn't required
to have any parameters (like a file name)

Better email headers for In-Reply-To and References

Reviewed-by: Peter Rotich <peter@osticket.com>

Make captcha text case-insensitive

Reviewed-By: Jared Hancock <jared@osticket.com>

Previous the options defined for the Mailer::send() function were confusing
when sending an In-Reply-To header

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.

Support ticket thread items in email templates

Reviewed-By: Peter Rotich <peter@osticket.com>

Strip quoted reply revisited

Reviewed-By: Jared Hancock <jared@osticket.com>

Order FAQ by question

Reviewed-By: Jared Hancock <jared@osticket.com>

Remove accidental inclusion of remote web page

Reviewed-By: Peter Rotich <peter@osticket.com>

* %{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

The XKCD index page was accidentally added when testing a new feature for
osTicket-1.8

Include category when searching the knowledge base 

Reviewed-By: Jared Hancock <jared@osticket.com>

Support non-standard port numbers for MySQLi

Reviewed-By: Peter Rotich <peter@osticket.com>

Mark tickets overdue which have no SLA

Reviewed-By: Peter Rotich <peter@osticket.com>

Make Crypto::random() more reliable on Windows

Reviewed-By: Peter Rotich <peter@osticket.com>

Handle parsing email if Reply-To header is missing

Reviewed-By: Peter Rotich <peter@osticket.com>

Reduce cost of deleting orphaned files

Reviewed-By: Peter Rotich <peter@osticket.com>

Support updating the source of the ticket

Reviewed-By: Peter Rotich <peter@osticket.com>

Die on redirect

Reviewed-By: Jared Hancock <jared@osticket.com>

Validate port during installation

Add help information about the non-standard port number to the popup tips in
the install screen.

Support MySQL 'localhost' connections using a non-standard port number.
Ordinarily, MySQL will ignore the port setting on *nix systems if the host
is specified as 'localhost'

Implements/Fixes #769

This patch makes openssl the preferred source of random data on Windows and
will only use mcrypt_create_iv on PHP 5.3.7 and newer.

Fixes #771

Fixes #772

Previous explain included a nested sub-select, which exponentially increased
the count of the rows to be examined. This patch eliminates one layer of
nesting on the sub-select and dramatically increases the performance finding
orphaned files.

Fixes #773

References:
http://www.osticket.com/forums/forum/osticket-1-7-latest-release/troubleshooting-and-problems-aa/9446-version-1-7-much-slower-than-1-6