Dynamic transit copy status messages

Dynamic transit copy status messages

Via string properties, it is now possible to attach custom messages
which are displayed in the transit alert dialog and appended to printed
transit receipts based on the status of the in-transit copy.

By status in this case, I mean the status the copy will return to once it
arrives at its destination, not the literal copy status, which will always
be 'in-transit'.

To apply such a message, add a string property to
server/locale/<locale>/circ.properties with the format:

staff.circ.utils.transit.copy_status_message.<status_id>=FOO

For example:

staff.circ.utils.transit.copy_status_message.16=This item is in status
Long Overdue, additional staff action may be required.\n\n

If a message is present which matches the ID of the status of the
in-transit copy, the configured message will be appended to the transit
alert and the receipt.

In the case of receipts, newlines are replaced with <br/>'s.  Plus, the
message will be added to all transit receipts (as last item in the header),
regardless of whether a custom receipt is used.

Signed-off-by: Bill Erickson <berick@esilibrary.com>