1. Using std::string parameter as the key of CCDictionary
2. Deep copy for CCDictionary and CCArray, the classes of elements's type must implement copyWithZone.
3. Added toBool() function to CCString.
4. Retina support for all platforms.
5. Include "CCString.h" and "cocoa/CCNS.h" in cocos2d.h.
6. Added a new constructor(CCArray::CCArray(unsigned int capacity)) for CCArray. And fixed a bug in CCArray.
7. Fixed a memory leak in CCLabelBMFont.cpp.
8. Fixed an error in strings.xml.