Bug 24820: Use 'date' instead of 'timestamp' for cashup

Bug 24820: Use 'date' instead of 'timestamp' for cashup

Prior to this patch we were comparing cash register action timestamp to
accountlines date fields to fetch the list of outstanding accountlines.

accountlines.date is a transient field used as 'updated_on' and so this
was a logical mistake. We should be using the 'date' field which is
fixed 'created_on' time.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>