Adding stats to Services and Destinations

[luizbafilho]

This PR adds statistics to Services and Destinations

[mqliang]

@luizbafilho LGTM. Could you please rebase.

[luizbafilho]

@mqliang Done!

[mqliang]

@luizbafilho It seems that you merge the master branch into your own branch and submit a pull request, instead of rebasing. You could do a rebase as follows:

• git remote add upstream https://github.com/mqliang/libipvs.git
• git remote update
• git checkout adding-statistics
• git rebase upstream/master, (and solve conflicts if need)
• git push -f origin adding-statistics

[luizbafilho]

@mqliang thanks for instructions. Done.

[mqliang]

LGTM.