Movement with left/right arrow keys.

Movement is hardcoded but it works.
Also fixed some typos that gave me a hard time figuring out why
movement was giving all sort of crazy problems. Very bad typos,
see gameplaysceneclassic.cpp, inputbag.cpp, inputbag.hpp and key.hpp
if you want to get goosebumps.

CMakeLists.txt

@@ -46,6 +46,7 @@ add_executable(${PROJECT_NAME}
 	src/gameplaysceneclassic.cpp
 	src/moverrelative.cpp
 	src/inputbag.cpp
+	src/moverleftright.cpp
 )
 
 target_link_libraries(${PROJECT_NAME}