Fix wayland backend build when debugging is enabled

Signed-off-by: Kalle Vahlman <kalle.vahlman@movial.com>
Protect logging symbols from C++ name mangling

Otherwise enabling debugging and C++ modules will result in
runtime linking errors.

Signed-off-by: Kalle Vahlman <kalle.vahlman@movial.com>
Merge pull request #60 from kvahlman/build-fixes

Build fixes