add %patron_display_name% macro to hold shelf

add %patron_display_name% macro to hold shelf

which shows either the patron alias or last name + first name + second name.

This is so we can, for example, mimic the print output of the very buried
Admin -> For Developers -> Local Administration -> Expired Holds Shelf Printable
Listing interface.

One could do this by setting their hold_slip template in the Receipt Template
Editor to look like this:

Header:
%SHORTNAME% %TODAY_TRIM%<br/>
<hr/>
<style type="text/css">
    body { font-size: 14pt; }
    td {
        padding-right: 1em;
        padding-bottom: 1em;
        border-bottom: 1px #999 dashed;
    }
    th {
        text-align: left; font-weight: bold;
        border-bottom: 1px #000 solid;
        border-right: 1px #000 solid;
        padding: 0.5em;
    }
</style>
<table>
<tr>
<th>Patron</th>
<th>Action</th>
<th>Type</th>
<th>Title</th>
<th>Author</th>
<th>Shelving Location</th>
<th>Call Number</th>
<th>Barcode</th>
</tr>

Lineitem:
<tr>
<td>%patron_display_name%</td>
<td>%post_clear_shelf_action%</td>
<td>%hold_type%</td>
<td>%title%</td>
<td>%author%</td>
<td>%current_copy_location%</td>
<td>%callnumber%</td>
<td>%current_copy%</td>
</tr>

Footer:
</table>

Signed-off-by: Jason Etheridge <jason@esilibrary.com>