[input] Clear button inputs when IN_ClearStates called

This fixes the annoying persistence of inputs when respawning and
changing levels. Axis input clearing is hooked up but does nothing as of
yet. Active device input clearing has always been hooked up, but also
does nothing in the evdev and x11 drivers.

include/QF/input/binding.h

@@ -351,7 +351,9 @@ void IN_ButtonAction (in_button_t *buttin, int id, int pressed);
 int IN_RegisterButton (in_button_t *button);
 int IN_RegisterAxis (in_axis_t *axis);
 in_button_t *IN_FindButton (const char *name);
+void IN_ButtonClearStates (void);
 in_axis_t *IN_FindAxis (const char *name);
+void IN_AxisClearStates (void);
 void IN_ButtonAddListener (in_button_t *button, button_listener_t listener,
 						   void *data);
 void IN_ButtonRemoveListener (in_button_t *button, button_listener_t listener,

libs/input/in_axis.c

@@ -75,6 +75,18 @@ IN_FindAxis (const char *name)
 	return Hash_Find (axis_tab, name);
 }
 
+static void
+axis_clear_state (void *_a, void *data)
+{
+	//FIXME what to do here?
+}
+
+void
+IN_AxisClearStates (void)
+{
+	Hash_ForEach (axis_tab, axis_clear_state, 0);
+}
+
 void
 IN_AxisAddListener (in_axis_t *axis, axis_listener_t listener, void *data)
 {

libs/input/in_button.c

@@ -227,6 +227,19 @@ IN_ButtonRemoveListener (in_button_t *button, button_listener_t listener,
 	}
 }
 
+static void
+button_clear_state (void *_rb, void *data)
+{
+	regbutton_t *rb = _rb;
+	button_release_cmd (rb->button);
+}
+
+void
+IN_ButtonClearStates (void)
+{
+	Hash_ForEach (button_tab, button_clear_state, 0);
+}
+
 static void
 in_button_shutdown (void *data)
 {

libs/input/in_common.c

@@ -587,6 +587,8 @@ IN_ClearStates (void)
 			rd->driver.clear_states (rd->data);
 		}
 	}
+	IN_AxisClearStates ();
+	IN_ButtonClearStates ();
 }
 
 #ifdef HAVE_EVDEV