Bug 14224: Allow patron notes about item shown at check in

Bug 14224: Allow patron notes about item shown at check in

This patch adds a "Note" input field to checked out items in the "your summary"
section. The field allows patrons to write notes about the item checked out,
such as "this DVD is scratched", "the binding was torn", etc. The note will be
emailed to the library and displayed on item check in.

Patch adds two fields to the "issues" table - "note" and "notedate".
Patch adds syspref "AllowIssueNotes" - default off.

Test Plan:
1) Apply this patch
2) Update database
3) Rebuild schema
4) Turn on 'AllowIssueNote' syspref
5) Check out three different items to a borrower (may be easiest to check
    out to yourself)
6) Log in as that borrower (or yourself) on the OPAC side and go to your
summary
7) Confirm text field shows under Note column for all checkouts. Set a
note for each issue, confirm all save.
8) Check the message_queue in mysql for the entries for ALL THREE issue
notes.
9) Disable javascript in your browser
10) Refresh your summary page. Confirm that you can no longer edit the
notes in the text field. Click the 'Create/edit note' button and confirm
you are redirected to a new page.
11) Confirm that the correct title and author show for the note button
you clicked.
12) Set the note and click Submit -> confirm you are redirected
back to summary page and note is saved
13) Confirm there is a new entry in message_queue
14) Enable javascript and go back to the your checkouts page in the
staff client for the borrower you issued the items to
15) Check in TWO items
16) Confirm that the issue notes show under the "Date due" column for
the two items you checked in, and are accurate to the item (i.e. the
right issue note under the right item)
17) Go to circ/returns.pl and check in the final item using the barcode.
Confirm the issue note shows and the date is formatted correctly.

Sponsored-by: Region Halland
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Marc Véron <veron@veron.ch>