LineItem.label was erroneously set to required - breaks tests

civicrm_line_item.label was erroneously changed (back) to required due to a bad merge from accounts branch to trunk.

Also discovered the civicrm_line_item.price_field_id still had an FK constraint with ON DELETE CASCADE. This is wrong because we NEVER want to have line_item rows deleted due to deletion of a price_field row. I've changed price_field_id to NOT REQUIRED and ON DELETE SET NULL. Also added code in 4.3.alpha1.mysql.tpl to drop and re-add that FK for existing sites.

Removed the api.required for price_field_id from api/v3/LineItem.php.

Ran api_v3_LineItemTest and it completes successful.

— original post —
'label' used to be an optional field for lineitem api - now it is compulsory due to it being 'Not Null' in the DB & having no default. Ditto qty

I have made qty required & set a pretty dumb default on label - ideally the BAO layer would be clever enough to put in the correct label since it has the price_field_id & price_field_value. I also made line_total required. Obviously it should be able to calculated itself. Hopefully someone will provide a patch @ the BAO layer.

I think the lineitem api is new enough that adding new required fields is OK.