Removed SDL_bool in favor of plain bool

We require stdbool.h in the build environment, so we might as well use the plain bool type.

If your environment doesn't have stdbool.h, this simple replacement will suffice:
typedef signed char bool;

test/testautomation_events.c

@@ -25,7 +25,7 @@ static int g_userdataValue2 = 2;
 #define MAX_ITERATIONS 100
 
 /* Event filter that sets some flags and optionally checks userdata */
-static SDL_bool SDLCALL events_sampleNullEventFilter(void *userdata, SDL_Event *event)
+static bool SDLCALL events_sampleNullEventFilter(void *userdata, SDL_Event *event)
 {
     g_eventFilterCalled = 1;
 
@@ -36,7 +36,7 @@ static SDL_bool SDLCALL events_sampleNullEventFilter(void *userdata, SDL_Event *
         }
     }
 
-    return SDL_TRUE;
+    return true;
 }
 
 /**