Update CCDirectorCaller.mm

First destroy CCDirector instance with  cocos2d::CCDirector::sharedDirector()->end() 

Then create new CCDirector instance with
cocos2d::CCApplication::sharedApplication()->run();

APP will crash at 
CCApplication::setAnimationInterval

[[CCDirectorCaller sharedDirectorCaller] setAnimationInterval: interval ];
Merge pull request #2247 from hailongiPhone/master

release && set nil