GCC 5 is able to prove that in some translation units the static Logger
instance is defined but never used, and generates an unused variable
warning for each one of them. These warnings become fatal errors when
building in debug mode, due to -Werror.
Silence the compiler by not declaring the unused variables.
refs #2767
Change-Id: Icacc579d917d660582221ef090954ec827f46149
Note that as of this commit, there are several changes in location of
compiled binaries in `build/` folder:
* `nfd` has been moved to `build/bin/nfd`
* `unit-tests` has been split into `unit-tests-core` and `unit-tests-daemon`
Change-Id: I2c830c117879edbaa5457d6423c13f0273285919
Refs: #1486
Junxiao Shi
Davide Pesavento
Yanbiao Li
Spyridon Mastorakis
Alexander Afanasyev
Steve DiBenedetto