common: Move settings to common from core.

- Removes a dependency on core and input_common from common.

src/input_common/mouse/mouse_input.cpp

@@ -2,7 +2,7 @@
 // Licensed under GPLv2+
 // Refer to the license.txt file included.
 
-#include "core/settings.h"
+#include "common/settings.h"
 #include "input_common/mouse/mouse_input.h"
 
 namespace MouseInput {

src/input_common/mouse/mouse_poller.cpp

@@ -5,8 +5,8 @@
 #include <mutex>
 #include <utility>
 
+#include "common/settings.h"
 #include "common/threadsafe_queue.h"
-#include "core/settings.h"
 #include "input_common/mouse/mouse_input.h"
 #include "input_common/mouse/mouse_poller.h"