NPE in network/configuration

Issues identified in network/configuration
1. NPE in network/configuration POST and DELETE when invalid subjectclasskey is given as input.
2. while posting network/configuration, an error in a field should result in 207 response. But it is giving error message as 400.

{ "code": 400, "message": "Error parsing config ports/of:0000000000000001/1/interfaces: Field \"names\" is invalid: Field is not allowed", "subjectKey": "ports", "subject": "of:0000000000000001/1", "configKey": "interfaces", "field": "names", "reason": "Field is not allowed" }

3. If there is an error in network configuration JSON, it stops there and does not commit the remaining configurations in the same JSON.