Initial version of new code for layer switch is added.

common/command.c

@@ -23,7 +23,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "debug.h"
 #include "util.h"
 #include "timer.h"
-#include "layer.h"
+#include "keyboard.h"
 #include "matrix.h"
 #include "bootloader.h"
 #include "command.h"