Bug 11689: Take new serial missing statuses into account in more places

Bug 11689: Take new serial missing statuses into account in more places

Bug 10851 introduced new missing status (codes 41,42,43,44), but in
GetSerials and _update_missinglist, they are not taken into account.

This patch corrects the issue.

To reproduce:
1/ Create a serial with 10 issues.
2/ Set different statuses on each one, with at least 6 missing statuses
(not only "Missing").
3/ Go on the subscription detail page, tab "Summary", the issues with a
new missing status are not listed in the missing issues list.
4/ On the "Issues" tab, all missing are listed (normally only 5 should
be listed.
5/ Apply the patch.
6/ Edit serial (to rewrite the missing list).
6/ Verify that steps 3 and 4 have now correct behavior.

Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works as described, passes QA script and tests.

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