Use more C++17 features

Mainly structured bindings, inline variables, and class template
argument deduction, plus many more smaller things.

Change-Id: I810d17e0adb470426e4e30c898e03b3140ad052f
diff --git a/daemon/table/fib.hpp b/daemon/table/fib.hpp
index a4b688f..6073533 100644
--- a/daemon/table/fib.hpp
+++ b/daemon/table/fib.hpp
@@ -36,6 +36,7 @@
 namespace measurements {
 class Entry;
 } // namespace measurements
+
 namespace pit {
 class Entry;
 } // namespace pit