Examples: disable GL related warnings on Mac + amend to ignore list.

examples/example_glfw_opengl3/main.cpp

@@ -7,6 +7,7 @@
 #include "imgui_impl_glfw.h"
 #include "imgui_impl_opengl3.h"
 #include <stdio.h>
+#define GL_SILENCE_DEPRECATION
 #if defined(IMGUI_IMPL_OPENGL_ES2)
 #include <GLES2/gl2.h>
 #endif

examples/example_glut_opengl2/main.cpp

@@ -17,6 +17,7 @@
 #include "imgui.h"
 #include "imgui_impl_glut.h"
 #include "imgui_impl_opengl2.h"
+#define GL_SILENCE_DEPRECATION
 #ifdef __APPLE__
     #include <GLUT/glut.h>
 #else

examples/example_sdl_sdlrenderer/main.cpp

@@ -38,7 +38,7 @@ int main(int, char**)
     if (renderer == NULL)
     {
         SDL_Log("Error creating SDL_Renderer!");
-        return false;
+        return 0;
     }
     //SDL_RendererInfo info;
     //SDL_GetRendererInfo(renderer, &info);