OVS events: Address all PR comments

OVS events: Address all PR comments

- Change OVS implementation to use suggested configuration:

   OvsDbAddress "127.0.0.1" "6640"
   OvsDbAddress "2001:DB8::c011:ec7d" "6640"
   OvsDbAddress "2001:DB8::c011:ec7d" "service-name"
   OvsDbAddress "unix:/path/to/socket"

- Update documentation;
- Change OVS utils to use getaddrinfo();
- Clean-up compilation warnings on FreeBSD system.
- Add IPv6 support;

Change-Id: I60ca700c15406c783b62ee52135266d67b60393a
Signed-off-by: Mytnyk, VolodymyrX <volodymyrx.mytnyk@intel.com>