Bug 10513: display a warning/message when returning a chosen item type

Bug 10513: display a warning/message when returning a chosen item type

This patch adds a new column to item types. Text in this column is
displayed as a warning when an item of the given type is checked in.
The type of message can also be chosen, affecting how the message is
displayed.

Use case: Items that are on inter-library loan can have a separate
item type, and when items of this type are checked in a message
saying something like "ILL! Remember to return it to the owning
library!" can be displayed.

To test:
- Apply the patch
- Go to Home > Administration > Item types administration
- Check that there is a new column, called "Check in message"
- Edit an item type and add a check in message
- Check that the check in message you added is displayed in the table
- Check in an item with an item type that has a check in message
- Check that the message is displayed
- Repeat the steps above, but select "Alert" instead of the default
  "Message" as the "Check in message type". Check that the message
  is displayed in a yellow alert box, not a blue message box.
- Check in an item with an item type that does *not* have a check
  in message, and make sure no false messages are displayed
- Create a new item type from scratch and check that it works
  the way it is supposed to
- Run the tests in t/ItemType.t, which are updated by this patch

This patch also removes backticks around column names in the
itemtypes table in installer/data/mysql/kohastructure.sql

UPDATE 2013-07-22
- Rebased on current master (no changes)
- Added "AFTER summary" to the SQL statement in updatedatabase.pl
- Added another placeholder on line 170 of admin/itemtypes.pl
Thanks Katrin!

UPDATE 2013-07-29
- Make this message independent of all other messages - thanks Owen!
- Make it possible to choose the type of message ("alert" or
  "message")

Sponsored-by: Kultur i Halland - Regionbibliotek
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Fixed some tabs to make the QA script happy.
All old and new tests pass.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>