Prompt end user for accessibility permission, from http://devstreaming.apple.com/videos/wwdc/2013/200xdx2x35e1pxiinm/200/200.pdf

accessibility_prompt.m

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
     CFMutableDictionaryRef options = CFDictionaryCreateMutable(NULL, 0,
     &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
     CFDictionarySetValue(options, kAXTrustedCheckOptionPrompt, kCFBooleanTrue);
     AXIsProcessTrustedWithOptions(options);
     CFRelease(options);
}