[NLopt/f20] (3 commits) ...merge differences from master

[Björn 'besser82' Esser]

Summary of changes:

  39e59d2... Rebuild to fix broken deps (*)
  59cc88e... fixed nlopt.pc to reflect the correct lib to link against (*)
  7adb864... merge differences from master (*)

(*) This commit already existed in another branch; no separate mail sent