Bug 4959 (Language inconsistencies on basket groups; skip confirmation when closing...

Bug 4959 (Language inconsistencies on basket groups; skip confirmation when closing basket)

This patch adds a new pref BasketConfirmations. This adds the option to skip
confirmations on closing and reopening a basket. If you skip the confirmation,
you do not create a new basket group.
The confusing line Create a purchase order (when closing a basket) is replaced
by Attach basket to a new basket group with the same name.
A warning for a null value on basketgroupid is fixed.

Rebased April 11.

Signed-off-by: Colin Campbell <colin.campbell@ptfs-europe.com>
Signed-off-by: Ian Walls <ian.walls@bywatersolutions.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>