forms: Better failsafe for __toString

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

This mostly helps when fields change types. If the type of the field
currently cannot convert previous data to a string (like if a short-answer
field was changed to choices), the textual representation of the PHP value
of the field data is given.

Allow new ticket without required contact fields

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

If a staff member creates a new ticket and cancels the user-lookup /
create-new-user dialog, and the contact information form has a required field
other than the name and email address fields, the ticket cannot be created
because the required fields for new clients are not shown and can therefore
not have a required value.

This patch allows new clients to be created without the required fields when
the ticket is created by staff members.

This issue was addressed for htmLawed, where the UTF-8 version of a
non-breaking space, 0xc2a0 would be collapsed to 0xa0, which would very
likely create an invalid Unicode character, and the text block would be
dropped or truncated.

sla: New SLA's default to alert when overdue

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

i18n: Allow Unicode characters in the username

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

Make tempnam play nice with open_basedir restriction on.

References:
http://us2.php.net/manual/en/function.tempnam.php#93256



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

Restrict access to closed tickets based on staff's access control.

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

Ensure the email doesn't already exist before creating it.

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

html: Drop xml processing instructions from email

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

mysqli: Numbers with leading zeros are strings

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

Fix ambiguous `due date` if specified as custom field

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

Allow manager to be set even when a department has no members

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

This is necessary to allow for creative department based access control and
alerts.

Fix canned append in non-HTML mode

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

Preserve inline image floating in ticket thread

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

Background: osTicket allows access to assigned open tickets (both personal
and team assignments) regardless of the assigned department or group. This
is necessary to allow staff to work on tickets in an otherwise restricted
department.

When a staff member closes a ticket, they're credited (ticket.staff_id is
set to staff's id) for the purpose of showing who closed the ticket.
osTicket mistakenly allowed continued access to closed tickets even when the
staff doesn't have access to the ticket based on departmental access.

Careful transcoding attachments with a charset

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

tnef: Strip null bytes from attachment filenames

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

If a non-text attachment specifies a charset in the content-type header,
don't transcode the content before saving it to the database. This can
corrupt attachments which have a header like the following:

Content-Type: application/pdf; charset=UTF-8

Since a PDF contains binary data, coercing it to UTF-8 encoding will drop
characters not valid in UTF-8 and will corrupt the attachment data.

Also support the TransportName in the properties list and prefer it over the
attachment-level attribute, as it is Unicode encoded.

filter: Implement priority 

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

The priority setting was broken when priority was added to the dynamic data

Register session close on shutdown at the start of session handling

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