Bug 5342: Serial claiming improvements: add a counter

Bug 5342: Serial claiming improvements: add a counter

This patch adds a new DB field serial.claims_count
This field already exists for late orders. It makes sense to introduce
it for serial.

Test plan:
0/
 a) Does not apply the patch.
 b) Remove all your claimissues notices and be sure you have some serial issues
    in late.
 c) remove email address for the vendor you will use.
 d) remove email address for the logged in user.
 e) Export claims using the csv export => The selected issues will be
 marked as claimed.
 f) logout/login (to update the email address).
1/ Apply the patch and execute the updatedb entry.
2/ Go on the Serials > Claims page
3/ Verify that you get a warning message 'No claimissue notice defined'
4/ Verify the vendor list is correct (with the number of serial in late.
You should not get any changes here.
5/ Select one vendor and verify that the issue which was claimed before
has a claim count set to 1.
6/ Verify that you are not able to send notification to the vendor.
7/ Create a claimissue notice.
Something like:
  <<LibrarianFirstname>>
  <<LibrarianSurname>>
  The following issues are in late:
  <order><<biblio.title>>, <<biblio.author>> (<<biblio.serial>>)</order>
8/ Go on the Serials > Claims page, the warning message does not appear
anymore.
9/ Select issues. Select a notice. And "Send notification".
You should get an error (no email defined for this vendor).
10/ Add an email for the vendor.
11/ Select issues. Select a notice. And "Send notification".
You should get an error (no email defined for your user).
12/ Add an email address to your user
logout/login
13/ Select issues. Select a notice. And "Send notification".
You should get a happy message: the email has been sent!
14/ The email will contain the order tags if bug 12851 is not
pushed/applied.

Signed-off-by: Paola Rossi <paola.rossi@cineca.it>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works as described, some small issues fixed in a follow-up.
Note: If you change the email address of your staff user, you will
have to log out and back in to make the change take effect.

Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>