Show ticket prview when a ticket number is clicked as opposed to ticket
view.
Add collaborator preview tab on ticket preview tool tip.

The change will allows staff to open a new ticket without going through the
"forced" user lookup popup. On cancel the staff is presented with a
simplified user info form with email and name being the only fields
required.

Fixup search for users with hits in an searchable authentication backend:

  * If there is a hit for the remote backend, include that in the search for
    local users by email address. If there is a hit locally for the same
    email address, then remove the remote hit from the search results.

Fixup typeahead results

  * Abort previous search requests when the user enters more text into the
    search fields. This makes the search box feel more consistent, and
    avoids the case where the user finishes typing and valid search hits
    never appear

Arrange templates in a group by their respective use in the system:

  * System Management Templates
  * Staff Ticket Templates (Alerts and Notices)
  * End-User Ticket Templates (Autoresponder)

This provides an interface to sort the templates and make them easier to
find and provides a nice place for new templates to be added without making
it increasingly more difficult to locate templates in the list.

This patch also fixes the missing templates in the drop-down list when
editing an implemented template.

This includes the initial concept of pluggable authentication along with the
initial concept for a plugin management system.

Previously the richtext editor introduced the loss of the collision
avoidance feature.

  * Upgrade to Redactor 9.1.7
  * Use a (x) icon from font-awesome for the dialog

Since the ticket thread is nested in a div now (required for inline videos
to be displayed correctly), the image hover caused the images to be shown at
the end of the thread entry body rather that its original location.

Fixes #64

Fixes #65

  * Dialogs are scrollable if too big
  * Placement does not respect scroll position now (fixed position)

Fixes #834 (again)

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

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

This means that drive-by mouse hovers, where the user likely did not intend
for the hover to actually popup the banner with the filename and download
button, do not trigger the popup. This patch changes the popup effect so
that it requires a 500ms hover before the popup is shown.