Improvements to BgpNeighborReq introspect.

Following changes have been made:

- Show local/remote ids as ip addresses instead of integers.
- Display configured and negotiated address families.
- Display configured and negotiated hold time values.
- Get rid of a few unused fields from the output.

Change-Id: Ib40720628dbaa721b1209e97cbfcc5fb3c23a99e