Update code style

Limit source code to 80 chars, and declare functions return type and
modifiers on a separate line.

This allows to avoid very long lines, and all function names are
aligned.

(We do this on VLC, and I like it.)

app/src/convert.h

@@ -15,21 +15,26 @@ struct complete_mouse_wheel_event {
     struct point position;
 };
 
-SDL_bool input_key_from_sdl_to_android(const SDL_KeyboardEvent *from,
-                                       struct control_event *to);
-SDL_bool mouse_button_from_sdl_to_android(const SDL_MouseButtonEvent *from,
-                                          struct size screen_size,
-                                          struct control_event *to);
+SDL_bool
+input_key_from_sdl_to_android(const SDL_KeyboardEvent *from,
+                              struct control_event *to);
 
-// the video size may be different from the real device size, so we need the size
-// to which the absolute position apply, to scale it accordingly
-SDL_bool mouse_motion_from_sdl_to_android(const SDL_MouseMotionEvent *from,
-                                          struct size screen_size,
-                                          struct control_event *to);
+SDL_bool
+mouse_button_from_sdl_to_android(const SDL_MouseButtonEvent *from,
+                                 struct size screen_size,
+                                 struct control_event *to);
+
+// the video size may be different from the real device size, so we need the
+// size to which the absolute position apply, to scale it accordingly
+SDL_bool
+mouse_motion_from_sdl_to_android(const SDL_MouseMotionEvent *from,
+                                 struct size screen_size,
+                                 struct control_event *to);
 
 // on Android, a scroll event requires the current mouse position
-SDL_bool mouse_wheel_from_sdl_to_android(const SDL_MouseWheelEvent *from,
-                                         struct position position,
-                                         struct control_event *to);
+SDL_bool
+mouse_wheel_from_sdl_to_android(const SDL_MouseWheelEvent *from,
+                                struct position position,
+                                struct control_event *to);
 
 #endif