Apple: Fixed example_osx_opengl2, renamed to example_apple_opengl2 + misc comments

examples/imgui_impl_osx.mm

@@ -1,10 +1,10 @@
 // ImGui Platform Binding for: OSX / Cocoa
 // This needs to be used along with a Renderer (e.g. OpenGL2, OpenGL3, Vulkan, Metal..)
+// [BETA] Beta bindings, not well tested. If you want a portable application, prefer using the Glfw or SDL platform bindings on Mac.
 
 // Issues:
 // [ ] Platform: Keys are all generally very broken. Best using [event keycode] and not [event characters]..
-// [ ] Platform: Mouse cursor shapes are not supported (see end of https://github.com/glfw/glfw/issues/427)
-// [ ] Test with another renderer back-end than OpenGL2. e.g. OpenGL3.
+// [ ] Platform: Mouse cursor shapes and visibility are not supported (see end of https://github.com/glfw/glfw/issues/427)
 
 #include "imgui.h"
 #include "imgui_impl_osx.h"
@@ -12,7 +12,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
-//  2018-06-XX: Initial version.
+//  2018-07-07: Initial version.
 
 // Data
 static clock_t  g_Time = 0;