new file,use next function，xml can not found，plist can。
CCFileUtils::sharedFileUtils()->fullPathFromName(std::string pszFilename)
log result:
Cocos2d: new:480/sprite_grid_block.plist
Cocos2d: after:/Users/mixiancheng/Library/Application Support/iPhone Simulator/6.1/Applications/9B6B955B-1E6B-41BC-AD49-65BDD0A9D761/test23.app//480/sprite_grid_block.plist
Cocos2d: new:480/sprite_grid_block.xml
Cocos2d: after:480/sprite_grid_block.xml