Use unitprice in neworder so that the value is saved in the database and so it will...

Use unitprice in neworder so that the value is saved in the database and so it will be the same field used as to receive shipments

http://bugs.koha-community.org/show_bug.cgi?id=6414
Signed-off-by: Nicole C. Engard <nengard@bywatersolutions.com>
Signed off with a note: this doesn't fix everything mentioned in the bug.
It also might clash with bug 4831 and should be tested with that patch.

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
(cherry picked from commit 0faf91c591cf8bd02f5e70cc14caeb5257f4d1c5)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>