Check for defaults even when inserting new node

There are situations where nodes get inserted without using the UI, e.g. when working with feeds or when creating nodes programmatically. In such cases, toc_node_node_insert() throws an error because the required values are missing.

The solution is to simply call toc_node_node_update() instead as this does all the tricks already and db_merge() takes care to know if we need to insert or update the db record.

A patch is on its way.