Standby lag polling

[melanholy]

Not entirely sure about the way I handled requests to lagging standbys . May need a little more thought.

[x4m]

Hi! This seems like an extremely valuable feature! Thanks!
I'm hesitating between mergaing as is and doing few API adjustements.
We need the feauture to be working on primary too. And, probably, it will work just fine if lag polling will return 0 lag.

[g0djan]

Hi, you have a huge list of files with conflicts due to PR with formatting.
Steps for rebasing.

save files that were changed in your PR
git checkout master
git pull
git checkout
git rebase -i HEAD~0 --onto master(this line delete all your changes, don't forget to save it)
copy back saved files to the repository
format files: find ./ -type f ( -iname *.c -o -iname *.h -o -iname *.cpp -o -iname *.hpp ) -exec clang-format -style=file -i {} ;
git commit -am "Name of PR"
git push -f
If you have a questions or want my help you can ask me here :)