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

Moved to an initial form which specifies the ticket's priority and issue and
changed the rendering to render things properly. Now the user can decide
where priority shows on the client side, and the priority privacy setting is
placed in the dynamic form wizard.

The standard form is added to every ticket without option. Extra forms can
be defined and associated with help topics which can additionally be added
to tickets upon creation. This allows for standardization of the dynamic
data location for searches and filtering.

Implemented advanced search for dynamic data. Along with reinstating the
basic ticket search on keywords

Implemented ticket filtering on dynamic data for both keyword searches as
well as searches for special fields (drop-down lists, etc.)

Phone number for users is now completely optional

Process inline attachments in thread entry and support inline images in
piped emails

Support inline images across the system, with draft support

Migrate to a single attachment table
    That way we don't need a new table for everything we need to attach an
    inline image to (like a signature, for instance)

Add richtext support for internal notes

Implement images on site pages

* Image paste in Redactor
* Make non-local images optional
* Placeholder for non-local images
* Fix local image download hover
* Don't re-attach inline images

Add overlay & loading spinner to client interface - shown on form submission to help cut down on double submits.