Add ecs_quit to signal that application should stop progressing world

.gitignore

@@ -1 +1,3 @@
 .DS_Store
+*.o
+*.dylib

include/private/types.h

@@ -221,6 +221,7 @@ struct EcsWorld {
     bool auto_merge;              /* Are stages auto-merged by ecs_progress */
     bool measure_frame_time;      /* Time spent on each frame */
     bool measure_system_time;     /* Time spent by each system */
+    bool should_quit;             /* Did a system signal that app should quit */
 };
 
 extern const EcsArrayParams handle_arr_params;

include/reflecs.h

@@ -129,6 +129,17 @@ REFLECS_EXPORT
 EcsResult ecs_fini(
     EcsWorld *world);
 
+/** Signal exit
+ * This operation signals that the application should quit. It will cause
+ * ecs_progress to return false.
+ *
+ * @time-complexity: O(1)
+ * @param world The world to quit.
+ */
+REFLECS_EXPORT
+void ecs_quit(
+    EcsWorld *world);
+
 /** Import a reflecs module.
  * Reflecs modules enable reusing components and systems across projects. To
  * use a module, a project needs to link with its library and include its header
@@ -239,7 +250,7 @@ void ecs_import(
  * @param delta_time The time passed since the last frame.
  */
 REFLECS_EXPORT
-void ecs_progress(
+bool ecs_progress(
     EcsWorld *world,
     float delta_time);
 

src/world.c

@@ -465,6 +465,7 @@ EcsWorld *ecs_init(void) {
     world->measure_frame_time = false;
     world->measure_system_time = false;
     world->last_handle = 0;
+    world->should_quit = false;
 
     ut_time_get(&world->frame_start);
     world->frame_time = 0;
@@ -618,7 +619,7 @@ EcsHandle ecs_lookup(
     return 0;
 }
 
-void ecs_progress(
+bool ecs_progress(
     EcsWorld *world,
     float delta_time)
 {
@@ -704,6 +705,14 @@ void ecs_progress(
             ut_sleepf(sleep);
         }
     }
+
+    return !world->should_quit;
+}
+
+void ecs_quit(
+    EcsWorld *world)
+{
+    world->should_quit = true;
 }
 
 void ecs_merge(