Fixed C++ compilation warnings

Signed-off-by: Vadim A. Misbakh-Soloviov <mva@mva.name>
Fixed unused result compilation warning

Signed-off-by: Vadim A. Misbakh-Soloviov <mva@mva.name>
Added basic LuaJIT support

Signed-off-by: Vadim A. Misbakh-Soloviov <mva@mva.name>