Fix the checked box "manual history" and fix the "null" value of serial next issue...

Fix the checked box "manual history" and fix the "null" value of serial next issue publication date

first part of this patch is the manual history must be checked if in database its checked.
Then, when you do not enter a value "Next issue publication date", a null value was set in the database, now, if empty, the  "first issue date" is set as "next issue".
And finally, We check that "manual history" is checked to show the "Subscription history" part. Actually its never shown.

Signed-off-by: Henri-Damien LAURENT <henridamien.laurent@biblibre.com>