[PATCH master v2] IPv6 ECMP support fixes for linux

[Mikhail Sennikovskii]

Hi Ondrej and all,

Here is the second version of the Linux IPv6 ECMP support patch.
It encorporates the adjustments, requested by Ondrej, as well
as some other modifications/fixes, accompanied by the comments 
in the code.

To save a bit of my time, I've created just one patch against the master for now.
Once we agree on the patch, I will create a patch agains int-new right away,
since adapting it to int-new is really strait-forward.

Also, as we discussed before, I will also create a separate patch to make 
the nl_parse_multipath use netlink_lp (linpool) instead of xrealloc, 
once we agree on the current netlink_lp approach that I've introduced.

Regards,
Mikhail