Bug 11551: Allow to search on parent ordernumber in histsearch.pl

Bug 11551: Allow to search on parent ordernumber in histsearch.pl

It is now possible to search on the order number on the order search
page.

Also searching on parent_ordernumber is possible, allowing one to
search to search children for a given order number.

Test plan:
1/ create a basket and 1 order with at least 2 items.
2/ receive partialy the order (receive only 1 item).
3/ note that a new ordernumber is created for item not received.
4/ go on the order search form and search for the original ordernumber
without checking the new checkbox "Display children too." => only 1
order (the parent) is displayed.
5/ now check the checkbox and search again => the parent order is
displayed but children too.

Signed-off-by: remy juliette <juliette.levast@iepg.fr>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works nicely, passes all tests and QA script.

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