Title: #421: Use pkg-config to detect version of wbclient
Please, do **not** close this PR.
There are other bugs without update for way more time that were not closed. Some of them
coming from you, @lslebodn.
I'll take a look on this soon but I'm a little bit too overwhelmed right now.
See the full comment at https://github.com/SSSD/sssd/pull/421#issuecomment-344345638