Bug 10514: improve visibility of Add item link on new order form

This patch converts the "Add" and "Clear" links
to the standard "submit/cancel" format inside a fieldset. This gives
them a little more visual weight.

Based on the changes made by Liz Rea and Jonathan Druart.

To test:

- create a basket
- add a record to it
- scroll down - the link to add item and cancel should both be more
  prominent now.
- Click "Add item" - it should add an item.

Signed-off-by: Liz Rea <liz@catalyst.net.nz>
I still feel weird about the button, but as two people have said they'd rather have the button, I'm alright with it I guess.
Really what I want is people to notice it's there and click it at the appropriate time. I hope this will help that issue.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Passes all tests and QA script.
Leaves the translation problems, but that needs more work and is
out of the scope of this bug.
Tested Add and Update functionality works correctly.

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