BUG-832 Refactor netconf connector

- Extract general API for remote connectors
- Split NetconfDevice into more classes
- Make data operations over netconf device in inventory binding aware (fixes 969)
- Add dependency on binding-broker
- Make connector crash if schema is not present for device
- Improve logging

Change-Id: Idf4fa4994b3ac067bd69e9cd629b6d8c225d7b77
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>
Merge "BUG-832 Refactor netconf connector"