function adds a new key/value pair to the specified parent object. Parent objects may contain
many keys and also sub-objects. The names of keys are not required to be unique: if you
twice with the same parameters you will create two identical keys in the database.
The parent object should already exist in the database, it can be OBJECT_PARENT_HANDLE
(the top-level object) but this is not recommended.
Unlike objects, keys do not have handles, so you can't go directly to a non-unique key
without using the
This call returns the CONFDB_OK value if successful, otherwise an error is returned.